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Fluorescent nanocellulose derived from Plectranthus barbatus for the selective detection of Pb(ii) ions in aqueous solutions
This study reports the synthesis of fluorescent nanocellulose from Plectranthus barbatus and its effective use as a fluorescent probe for the detection of Pb(ii) ions in aqueous solutions. Nanocellulose, a nanoscale derivative of cellulose, is used in a variety of applications, such as sensing, food packaging, and biomedical applications, owing to its characteristic properties. In sensing applications, it is mostly used as a support or substrate for the sensing probe. Nanocellulose shows intrinsic fluorescence, which can be harnessed for sensing applications. This underexplored research domain holds significant potential for developing sustainable and cost-effective sensing materials. We synthesized nanocellulose from Plectranthus barbatus (PBNC) and employed it as a fluorescent probe for the detection of Pb(ii). To the best of our knowledge, this is the first report demonstrating the potential of fluorescent nanocellulose for metal ion detection. The properties of fluorescent nanocellulose, PBNC, were studied using Fourier Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Photoluminescence (PL) spectroscopy. The fluorescence intensity of the nanocellulose was remarkably quenched in the presence of Pb(ii) ions selectively. The detection limit (LOD) of Pb(ii) using PBNC was found to be 2.7 nM. PBNC is a novel autofluorescent material that functions as an efficient nanosensor for the detection of Pb(ii) ions, and its applications can be extended to bio-imaging and sensing in biological, chemical, and environmental samples. This journal is The Royal Society of Chemistry, 2026. -
Ion-imprinted carbon dots: rationally designed fluorescent probes for the detection of selected metal ions from aqueous solutions
Photoluminescence properties of Carbon Dots (CDs) have been leveraged for their use as sensors for a variety of analytes, including inorganic ions, organic molecules, and biomolecules. The selective fluorescence response of CDs to specific analytes is generally not pre-designed. Rationally designed synthesis of CDs with pre-defined selectivity to specific analytes is a less explored avenue. This study presents a novel method for the customized synthesis of CD fluorescent probes and an ion-imprinting-based selective detection of metal ions using these CDs. Poly(sodium 4-styrenesulfonate) [PSS] treated with Cd(ii) ions was used as the precursor for preparing Cd-imprinted CDs, and a modified form of these CDs was used for the sensing of Cd(ii) in aqueous solutions. As synthesized CDs have Cd(ii) ions on their surface, which were subsequently removed through appropriate chemical treatment. This removal results in binding sites of Cd(ii) ions on the CDs. Formation of such binding sites results in alterations of the fluorescence of CDs. Exposure of these particles to analytes containing Cd(ii) ions leads to the re-occupation of the binding sites by the metal ions, resulting in a distinct fluorescence response, which serves as the sensing readout. Effectiveness of this ion-imprinting approach is demonstrated by the selective and sensitive fluorescence response of the CDs towards Cd(ii) ions, with a limit of detection (LOD) of 3.62 nM. This strategy of Cd(ii) detection using ion-imprinted CDs represents a novel effort in CD-based sensors, and this can be extended to the sensing of other cations also. This journal is The Royal Society of Chemistry, 2025 -
Unveiling the supercapacitive behavior of electrospun Cr2CTx/carbon nanofiber membrane
A novel electrospinning-based strategy was employed to fabricate Cr2CTx/carbon nanofibers using Cr2CTx MXene and polyvinyl alcohol (PVA) as precursors. This approach enables the formation of porous, conductive composite MXene layers dispersed in carbon nanofibers. The resulting material exhibited notable supercapacitive performance, delivering 338.8 F g?1 capacitance, 67.7 Wh kg?1 energy, and 1998 W kg?1 power density. This journal is The Royal Society of Chemistry, 2025 -
Ethylenediamine modified carbon nanospheres from biomass for selective membrane filtration
The present work investigates the antifouling properties dye and antibiotic removal efficiency of PVDF/E-CNS membranes. Carbon nanospheres (CNS) derived from rice husk (RH) were pyrolyzed at 800 C. Further, ethylenediamine functionalized carbon nanospheres (E-CNS) were obtained via in situ decoration of ethylenediamine on acid-functionalized carbon nanospheres (O-CNS). The synthesized E-CNS were characterized by techniques such as XRD, FESEM, Raman spectroscopy, FTIR and BET. The membranes were fabricated by integrating E-CNS at varying loadings (0.10.7 wt%) via a non-solvent induced phase separation (NIPS) technique. The membrane properties were assessed through FESEM, water contact angle measurements, pure water flux, antifouling studies and membrane rejections. In comparison to the other developed membranes, PVDF-2 with 0.3 wt% E-CNS loading displayed optimal performance, pure water flux (PWF) of ?318.90 L m?2 h?1, flux recovery ratio (FRR) > 90% up to three cycles, improved contact angle (80.24 to 68.44) and reduced roughness. Furthermore, PVDF-2 achieved dye rejection of methyl orange (MO 93.2%) and rhodamine B (RB 94.6%), and antibiotic rejection of amoxicillin (AM 93.8%) and tetracycline (TC 94.1%), respectively. These findings demonstrate the integration of E-CNS derived from a bio-source, making them a promising additive to improve PVDF membrane performance. This journal is The Royal Society of Chemistry -
Hierarchically porous RhB-encapsulated ZIF-7 as a dual-emission fluorescence probe for ultrasensitive detection of melamine in infant formulations
Melamine is an unauthorized food additive and a highly concerning adulterant in foods that can occur either accidently or intentionally in dairy products, with potential health risks upon exposure to higher concentrations. An ultrasensitive fluorescent probe based on dual emissive RhBx@ZIF-7 was developed to detect melamine. In this study, a fluorescent dye, Rhodamine B (RhB), was successfully encapsulated into the metal-organic framework (MOF) pores of ZIF-7 to form a fluorescent probe (RhB30@ZIF-7), with dual emission properties to enable the detection of melamine at low concentrations. RhB30@ZIF-7 was optimized by varying experimental parameters, including temperature (25 C), pH (7.0), incubation time (10 min), and probe concentration (1 mg mL?1), to enhance its sensitivity and selectivity. The observed fluorescent quenching towards melamine was primarily attributed to the mechanisms of the internal filtering effect (IFE), due to absorption of the excitation wavelength by melamine, causing a turn-off response in the system. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.47 ?M and 1.4 ?M, respectively, with an R2 of 0.99. This study reveals the previously unexplored enhanced fluorescence of RhB30@ZIF-7 and elucidates the contribution of the intermolecular interaction between RhB and ZIF-7 to fluorescence sensing, paving the way for food safety monitoring. 2025 RSC. -
Exploring a GE/Nafion/Co-MOF nanosheets/CuO NPs/GOx powered electrochemical biosensor for ultrasensitive detection of rebaudioside A
Rebaudioside A (Reb A) is a natural, non-nutritive sweetener highly prevalent in the global sweetener market and widely preferred by consumers. In this study, an advanced electrochemical biosensor was developed for sensing Reb A, using a modified graphite rod electrode extracted from discharged ZnC batteries. The electrode was fabricated using a layer-by-layer strategy with Nafion, Co-MOF nanosheets, CuO NPs, and glucose oxidase (GOx) enzyme. The nanomaterials were characterized by UV-vis, FTIR, DLS, zeta potential measurements, XRD, Raman, SEM, TEM, EDS, and XPS techniques. Electrochemical characterization via Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) revealed a significant enhancement in electrical conductivity and increased electroactive surface area. The designed biosensor exhibited a sharp oxidation peak at 0.16 V due to ester bond cleavage in Reb A, which was further amplified in the presence of GOx, resulting from hydroxyl oxidation and hydrogen peroxide generation. Differential pulse voltammetry (DPV) demonstrated a linear response over a concentration range of 2.014 M (R2 = 0.993) with a limit of detection (LOD) of 0.23 M. The sensor displayed excellent analytical performance, with repeatability, reproducibility (RSD = 3.9%), and stability. Additionally, recovery studies confirmed its accuracy, ranging from 97% to 98.17%. Further, the molecular docking studies confirmed strong Reb AGOx interactions (?7.26 kcal mol?1), supporting the biosensor's specificity. The developed biosensor demonstrates excellent analytical performance, making it highly suitable for routine laboratory analysis of sweeteners in complex food matrices. This journal is The Royal Society of Chemistry, 2026 -
Advanced electrochemical detection and profiling of the antihypertensive drug atenolol via a SPION-activated carbon nanocomposite interface
This study reports the synthesis of superparamagnetic iron oxide nanoparticles (SPIONs), activated carbon (AC) and SPION-AC nanocomposites using a simple hydrothermal method. Characterization of the synthesized materials includes dynamic light scattering, X-ray diffraction, field emission scanning electron microscopy, high resolution transmission electron microscopy, and vibrating sample magnetometry, along with electrochemical characterization studies such as electrochemical impedance spectroscopy. Among the SPION-AC nanocomposites, SPION-15%AC was employed to modify a glassy carbon electrode (GCE). The synergistic interaction between SPION and AC significantly enhanced the electrochemical properties of the system, leading to the development of a highly efficient platform for the detection of the antihypertensive drug atenolol (ATN) in commercial tablet samples. The sensor demonstrated excellent performance, with a linear detection range from 1.21 ?M to 285 ?M. With a low detection limit (LOD) of 0.401 ?M, the sensor offers precise quantification of ATN, making it a promising tool for improving patient care. High selectivity, reproducibility, and excellent recovery in complex pharmaceutical matrices further highlight the potential of this sensor for biomedical and clinical applications. 2025 RSC. -
CuNi-PTC metal-organic framework: unveiling pseudocapacitive energy storage and water splitting capabilities
Metal-organic frameworks (MOFs), owing to their distinctive structural properties and customizable functionalities, have been garnering significant attention in the pursuit of advanced energy storage and conversion technologies. In this work, a bimetallic MOF, CuNi-PTC, has been synthesized through a straightforward method. Investigations reveal its potential as a high-performance electrode material for supercapacitors and as an electrocatalyst for water splitting. The CuNi-PTC MOF features a large specific surface area, hierarchical porosity, and strong structural stability, as evidenced by spectroscopic and electron microscopy analyses. As a supercapacitor electrode material, CuNi-PTC delivers an impressive specific capacitance of 1066.24 F g?1 at a current density of 1 A g?1, along with excellent cycling stability, retaining 94% of its capacity after 5000 charge-discharge cycles. Additionally, the electrocatalytic performance of CuNi-PTC for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) was assessed, showing overpotentials of 212 mV for the HER and 380 mV for the OER at a current density of 10 mA cm?2, along with exceptional long-term durability. 2025 RSC. -
Biomass-derived carbon supported cobalt-phospho-boride as a bifunctional electrocatalyst for enhanced alkaline water splitting
Developing efficient and low-cost bifunctional electrocatalysts for overall water splitting in order to reduce the future energy crisis is crucial and challenging. Herein, a facile two-step fabrication via pyrolysis and chemical reduction was used for the synthesis of biomass-derived carbon-based electrocatalyst (MT) from mulberry bark and its subsequent modification with cobalt phospho-boride (MT/CoPB) for efficient bifunctional electrocatalysis in alkaline media. The effect of B/P ratios and carbon-to-metal ratios on electrocatalytic performance of HER was investigated. Notably, the optimized MT/CoPB catalyst (B/P = 5, C : M = 2 : 1) exhibited a lower overpotential of ?86 mV for HER and 310 mV for OER to reach the current density of 10 mA cm?2. The robust electrocatalytic performance of MT/CoPB towards the HER and OER was attributed to the combined effect of carbon and CoPB. Notably, it achieved a low cell voltage of 1.59 V to reach a current density of 10 mA cm?2, also maintaining reliable long-term stability. Characterization studies revealed that the enhanced performance was due to the amorphous structure of the catalyst, high electrochemical surface area, and efficient charge transfer. This work demonstrates the potential of biomass-derived carbon-based materials in the development of cost-effective and durable electrocatalysts for water splitting and green hydrogen production. 2025 RSC. -
Sustainable fabrication of arecanut waste-based polymer blend adsorbents for enhanced lead(ii) ion removal from water
Heavy metal contamination in water systems leads to critical environmental and health challenges, necessitating sustainable remediation technologies. This study presents a unique approach utilising arecanut organic residue, an abundant agricultural waste, for the removal of lead from water. A bioadsorbent composite film was synthesised using chitosanpolyvinyl alcohol (PVA) incorporated with arecanut organic residue by solvent casting. The physicochemical properties of the films were characterised by XRD, FTIR, optical profilometry, BET surface area and SEM analyses. The adsorption efficiency of the synthesised films was tested by examining the removal of Pb(ii) from water. The bioadsorbent films demonstrated a Pb(ii) removal efficiency of 94.6% from 5 ppm solutions at pH 6 within 60 minutes at 70 C using 0.5 g of the film. Optimisation studies revealed the critical role of functional group availability and film porosity of the polymer blends, along with experimental conditions that enhanced the adsorption capacity. Kinetic studies also confirmed the results obtained from the optimisation studies. The adsorption kinetics followed a pseudo-second-order model, and isotherm analysis confirmed Langmuir-type adsorption. The sustainable bioadsorbent exhibited good reusability, maintaining performance over multiple cycles. This journal is The Royal Society of Chemistry, 2026 -
Nature-inspired ?-MnMoO4nanocubes from Arachis hypogaea for next-generation wastewater treatment and organic pollutant catalysis
In this study, bimetallic ?-MnMoO4 nanoparticles (NPs) were successfully synthesized via a one-step solution combustion method using Arachis hypogaea (peanut) seed powder as a green fuel. This eco-friendly route was adopted to explore the adsorption, photocatalytic, and catalytic properties of the resulting NPs. The structural, morphological, and optical characteristics of ?-MnMoO4 NPs were systematically characterized using XRD, FTIR, UV-vis, and PL spectroscopy, SEM, and EDX techniques. Notably, ?-MnMoO4 NPs demonstrated excellent adsorption capability toward methylene blue (MB) dye, achieving a removal efficiency of 86.70%, which was primarily attributed to their negatively charged surface. Moreover, the nanoparticles demonstrated a remarkable photocatalytic activity, achieving 81.55% degradation of MB through the photo-oxidation of water into hydroxyl (?H) radicals by photogenerated holes. Beyond dye remediation, the study further explored the catalytic capabilities of o-phenylenediamine via oxidative condensation with substituted aromatic aldehydes to synthesize benzimidazole derivatives, achieving yields ranging from 35% to 85%, depending on the substituents used. This integrated approach highlights the potential of ?-MnMoO4 NPs not only in pollutant removal but also in facilitating the green synthesis of high-value chemical products, demonstrating promising applications in environmental remediation and fine chemical industries. This journal is The Royal Society of Chemistry, 2026 -
Fluorescence switching via competitive ESIPT and spirolactam ring opening in a multifunctional rhodamine B probe for selective detection of Cu2+ and OCl?: theoretical insights with anticancer and biosensor activity
A multifunctional ESIPT-based rhodamine-derived probe (BHS) was synthesized and developed as a colorimetric and fluorometric sensor for the selective detection of copper (Cu2+) and hypochlorite (OCl?) in aqueous solutions. Initially, BHS exhibits intense whitish blue fluorescence due to the active excited-state intramolecular proton transfer (ESIPT) mechanism within the molecule. However, upon interaction with Cu2+ and OCl?, noticeable changes in absorption and fluorescence occur, attributed to the inhibition of ESIPT resulting from analyte binding with BHS, leading to spirolactam ring opening. Furthermore, significant Stokes shifts in absorption (?? = 34 nm and 170 nm for Cu2+, and 163 nm for OCl?) and emission (?? = 67 nm for both Cu2+ and OCl?) further confirm this transformation. The spirolactam ring opening is induced by Cu2+ coordination, whereas for OCl?, it is triggered by oxidative cleavage. To explore potential biological applications, fluorescence titration experiments were conducted to study the interactions of the BHS-Cu2+ complex with ct-DNA and the transport protein bovine serum albumin (BSA). Additionally, molecular docking studies were performed to assess these interactions, while DFT calculations were employed to optimize the structures of BHS and its Cu2+ complex. The fluorescence changes of BHS in the presence of Cu2+ and OCl? in biological samples have been examined by the anticancer and biosensor activity of BHS in HCT-116 colorectal cancer cells. 2025 RSC. -
An MoS2/PEDOT:PSS-based flexible NIR-responsive soft actuator
The development of sophisticated smart devices heavily relies on flexible soft actuators combined with near infrared (NIR) light responsive two-dimensional (2D) materials. Soft robots provide a number of benefits, such as flexibility, high sensitivity, compliance and security. Amidst many manufacturing and driving approaches, light has surfaced as a facilitator, aiding in the fabrication of soft actuators. Using few-layered molybdenum disulphide (MoS2) and poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT:PSS), the current work aims to introduce a polymer nanocomposite film for soft actuator applications under NIR light exposure. The actuation behavior was impacted by PEDOT:PSS under NIR light exposure. In order to incorporate controllable deformation of the actuator, the photothermal properties of the composite film were investigated. In situ Raman spectroscopy and the density functional theory (DFT) calculation explain the structural change and energy optimization of PEDOT:PSS. A soft insect was further designed based on this photothermal property, which can deform under light exposure. Therefore, such flexible design has huge potential for soft robotics applications in modern technologies. 2025 RSC. -
Exploring pseudocapacitive performance in Cr2CTx/NiFe2O4 composites: experimental insights
The growing demand for sustainable and efficient energy storage systems has driven the development of advanced, durable, and cost-effective materials. This study introduces heterostructures of 2D Cr2CTx MXene and NiFe2O4, leveraging their synergistic properties, such as high conductivity, surface termination groups (-OH, -O, and -F), tunable surface chemistry, and rich redox activity. Comprehensive structural and morphological characterization confirms the enhanced functionality of Cr2CTx/NiFe2O4, which exhibits a remarkable specific capacitance of 1719.5 F g?1 with 88% retention over 5000 cycles in a three-electrode system. Additionally, the asymmetric supercapacitor device demonstrates a specific capacitance of 486.66 F g?1, an energy density of 97.66 W h kg?1, and a power density of 1203.95 W kg?1, retaining 94% of its capacitance after 5000 cycles. A plausible charge transfer mechanism in the composite is discussed, providing new insights into the synergistic Cr2CTx/NiFe2O4 heterostructures as high-performance materials for energy storage applications. 2025 The Royal Society of Chemistry. -
Hydrous nickel oxyhydroxide thin films on copper foil as robust electrocatalysts for alkaline oxygen evolution
Balancing catalytic activity and durability remains a major challenge for nickel-based oxygen evolution reaction (OER) electrodes, especially when supported on earth-abundant metals. Here, we demonstrate how the electrodeposition environment governs the structural and electrochemical evolution of nickel coatings on copper foil toward hydrous NiOOH active layers. Nickel was electrodeposited from sulfate baths at pH 3 and 4 to yield compact (Ni-Cuf-3) and hierarchically nodular (Ni-Cuf-4) films, respectively. Structural and electrochemical analyses reveal that deposition pH dictates the oxidemetal coupling and, consequently, the OER performance. Ni-Cuf-4 exhibited a lower overpotential (434 mV at 50 mA cm?2) and approximately tenfold higher Cdl (2.68 mF cm?2vs. 0.221 mF cm?2), corresponding to a larger density of electrochemically accessible sites. In contrast, Ni-Cuf-3 delivered a higher turnover frequency (TOF ?1 O2 s?1 per Ni site) and superior durability (?60 h at 800 mA cm?2). Impedance spectroscopy highlights distinct interfacial charge transfer characteristics arising from the different film morphology. Importantly, both electrodes achieve reduced nickel loading while suppressing copper dissolution, offering a sustainable pathway to durable, cost-effective OER catalysts. This journal is The Royal Society of Chemistry, 2026 -
High-performance Zn(ii)-based coordination polymer as an electrode material for pseudocapacitive energy storage and hydrogen evolution
Recently, multifunctional materials for energy storage and production have been investigated to address diverse energy challenges. However, innovative methodologies focusing on the design and synthesis of novel materials remain essential to effectively tackle persistent challenges such as material degradation, high overpotentials, low conductivity, inferior cycling performance, elevated resistance, and high production costs. Working along these lines, we report a simplistic gram-scale synthesis, characterization, and excellent electrochemical behavior of a Zn(ii)-based coordination polymer (COP) abbreviated as Zn(DAB). It has been obtained in quantitative yields through a facile one-pot reaction between N4-ligand, 3,3?-diaminobenzidine (DAB), and Zn(ii) ions, derived from Zn(OAc)22H2O, at room temperature. The proposed structure of the COP was established through a series of standard spectroscopic and electron microscopic analyses. These methods unveiled the self-assembly of indefinitely long coordination strands, resulting in a two-dimensional (2D) layered structure. Zn(DAB), when probed for its electrochemical characteristics, reveals exemplary results. The material showed a high specific capacitance of 2091.4 F g?1, calculated at 1 A g?1 with 92% retention over 5000 charge-discharge cycles. Additionally, the COP also exhibited a subservient overpotential of 263 mV at a current density of 10 mA cm?2 for the hydrogen evolution reaction. These results highlight the promising potential of Zn(DAB) as a multifunctional electrode material for sustainable energy applications. 2025 The Royal Society of Chemistry. -
Designing in situ nanostructured MWCNT-phloroglucinol modified webs for electrochemical-based dual screening of stress biomarkers
Phloroglucinol (PG), or benzene 1,3,5-triol, is an essential phenolic compound and a vital tannin. In this study, we developed a tannin-phloroglucinol (PG) derived redox mediator for the detection of glutathione (GT) and H2O2 on a glassy carbon electrode (GCE) modified with a multiwalled-chitosan composite. The PG redox platform was prepared using a cyclic voltammetric approach in pH 7 aqueous buffer media without any additional surfactant/chemical moieties. A highly stable, fouling-free surface confined redox characteristic was observed at an apparent electrode potential of E0? = ?0.196 V (A1/C1) and 0.05 V (A2/C2) vs. Ag/AgCl was observed. The as-prepared electrochemical platform achieved an ultra-low limit of detection (LOD) for glutathione (GT) of 0.16 M and LOQ of 2.08 M using a sustainable platform. In addition, it exhibited high selectivity for GT in the presence of various interfering analytes. In addition, the modified platform was extended to hydrogen peroxide (H2O2) sensing at ?0.196 V vs. Ag/AgCl with a LOD of 5.4 M in PBS buffer media at v = 10 mV s?1. The GCE/MWCNT-Chit@PG-Redox demonstrated robust performance in a proof-of-concept experiment for analyzing GT and H2O2 in real samples using a standard addition approach with good recovery values. This journal is the Owner Societies, 2026 -
Development of a natural product-based selective fluorescent sensor for Cu2+ and DNA/protein: insights from docking, DFT, cellular imaging and anticancer activity
The natural product seselin (SS), was synthesized and characterized spectroscopically for the selective detection of Cu2+ and biomolecules such as ct-DNA and BSA. The probe exhibits strong bluish emission in a MeOH-H2O (7 : 3, v/v) HEPES buffer solution (pH 7.4) at 453 nm. Upon exposure to Cu2+, the SS solution shows a selective fluorescence turn-off with a binding constant of 2.13 105 M?1 and a detection limit of 3.48 10?8 M. The HOMO-LUMO energy gap of the probe SS decreases from ?E = 7.97 eV to ?E = 7.77 eV upon binding with Cu2+, indicating enhanced stability due to ligand-metal complex formation. Significantly, the ligand SS exhibits fluorescence enhancement in the presence of ct-DNA and BSA, resulting in a visible fluorescence change from colorless to blue, with binding constants of 4.8 104 M?1 and 4.7 104 M?1, respectively. The binding interactions of SS with biomacromolecules have been explored through molecular docking studies, revealing that the probe can serve as a promising anti-cancer and anti-viral agent. Furthermore, the probe SS demonstrates potent anticancer activity in treatments involving MCF-7 and HLC cells. Additionally, the probe SS is capable of detecting intracellular Cu2+ in live MCF-7 cell lines. 2025 The Royal Society of Chemistry. -
Selective dual-mode detection of reactive oxygen species and metal ions by chemodosimetric vs. chelation pathways: fluorescence turn-on with OCl? and Zn2+/Mn2+, employing theoretical, practical, and bioimaging applications
An indole-coupled diaminomaleonitrile-based fluorescent chemosensor IMA has been designed and developed for the selective detection of ROS (OCl?) and metal ions Zn2+ and Mn2+via chemodosimetric and chelation pathways respectively. The selective sensing of OCl? is induced by a method of oxidatively cleaving of the imine bond of IMA, forming free indole aldehyde, which results in a 21-fold enhancement of fluorescence at 521 nm, with a detection limit of 2.8 M. On the other hand, the selective binding of IMA with Zn2+ and Mn2+ results in chelation-induced enhanced fluorescence (CHEF) and increased intermolecular charge transfer (ICT), leading to a 4-fold and 3-fold fluorescence enhancement at 432 nm and 435 nm, with the detection limits of 12.71 M and 17.34 M, respectively. UV-vis spectroscopy, fluorescence, DFT study, mass spectra, 1H-NMR analysis, and Job's plot analysis have been used to validate the sensing mechanism of IMA with OCl?, Zn2+, and Mn2+. For practical applications, the binding of IMA with OCl? has been utilized in the detection of commercial samples like bleaching powder and water analysis. Bio-imaging studies were conducted with IMA in the presence of OCl? and Zn2+ using green gram seeds in a physiological medium. 2025 The Royal Society of Chemistry. -
Polypyrrole functionalized MoS2 for sensitive and simultaneous determination of heavy metal ions in water
Assessing heavy metal ion (HMI) contamination to sustain drinking water hygiene is a challenge. Conventional approaches are appealing for the detection of HMIs but electrochemical approaches can resolve the limitations of these approaches, such as tedious sample preparation, high cost, time consuming and the need for trained professionals. Here, an electrochemical approach is developed using a nano-sphered polypyrrole (PPy) functionalized with MoS2 (PPy/MoS2) by square wave anodic stripping voltammetry for the detection of HMIs. The developed sensor can detect Pb2+ with a limit of detection of 0.03 nM and a sensitivity of 36.42 ?A nM?1. Additionally, the PPy/MoS2 sensor was employed for the simultaneous detection of HMIs of Cd2+, Pb2+, Cu2+ and Hg2+. The reproducibility, stability and anti-interference studies confirm that the sensor can be used to monitor HMI contamination of water. 2025 The Royal Society of Chemistry.