Valorization of coconut waste and Lawsonia inermis for the synthesis of NH4CoPO4·H2O/graphene oxide nanocomposite sensor material for ultrasensitive dopamine detection
- 1School of Advanced Sciences, Vellore Institute of Technology Chennai – 600127 India
- 2Centre for Advanced Materials and Innovative Technologies, Vellore Institute of Technology Chennai – 600127 India
- 3School of Electronics Engineering, Vellore Institute of Technology Chennai – 600127 India
Abstract
A green and environment-friendly approach to bio-inspired synthesis of ammonium cobalt phosphate hydrate/graphene oxide (NH4CoPO4·H2O/GO(G)) nanocomposite was developed using the leaf extract of Lawsonia inermis as a natural reducing agent and stabilizer. To enhance the electrical conductivity and electrochemical functionality, graphene oxide (GO) was introduced into the composite, which was prepared using a modified Hummer's method from coconut shell waste. The XRD analysis confirmed the successful synthesis of the biomass-derived GO(G) and NH4CoPO4·H2O/GO(G) nanocomposite. Comprehensive characterization using field-emission scanning electron microscopy (FE-SEM), XRD, UV-visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) provided information on the structural, morphological, optical, vibrational, and chemical-state characteristics of the synthesized material. The NH4CoPO4·H2O/GO(G) nanocomposite was modified on a glassy carbon electrode (GCE), and its sensing performance was evaluated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods for electrochemical dopamine (DA) detection. The modified GCE exhibited higher electrocatalytic performance for DA oxidation, and this improvement was explained by the synergistic effect between NH4CoPO4·H2O(G) and GO(G), which promotes electron transfer and thus increases the oxidation current. The sensor had a linear response to DA in the concentration range of 5–35 µM with a sensitivity of 34.097 µA µM−1 cm−2 and a detection limit of 0.28 µM under optimal conditions. The sensor also exhibited good stability, repeatability and selectivity, which further suggests the viability of green synthesized NH4CoPO4·H2O/GO(G) nanocomposite as a green electrode material for electrochemical DA sensing applications.
Related
- Synthesis of Dual Opto-Magnetic Property Bearing Nanocomposite and its Utility in the Detection of Cu2+ Ions
- Tuning the fluorescence response of Zn-MOFs through ligand replacement for ultrasensitive metronidazole detection
- Squaramide-based ultrasensitive and reversible colourimetric dual sensor for the detection of copper and metal-ion-assisted acetate anion
- Optimized Synthesis and Properties of Dumbbell-Shaped NaYF4:Yb,Tm@NaGdF4:Eu@NH2-MIL-53(Fe) Core–Shell Nanocomposite
- MOF / juniper leaf biochar hybrid for ultrasensitive and selective electrochemical detection of carbendazim in food
BibTeX
@article{kavitha2026valorization,
title = {{Valorization of coconut waste and Lawsonia inermis for the synthesis of NH4CoPO4·H2O/graphene oxide nanocomposite sensor material for ultrasensitive dopamine detection}},
author = {V. Kavitha and G. Lakshmi Priya},
journal = {RSC advances},
year = {2026},
month = oct,
doi = {10.1039/d6ra09550j},
url = {https://europepmc.org/article/PMC/PMC13673524},
note = {CC BY-NC},
}
RIS
TY - JOUR
TI - Valorization of coconut waste and Lawsonia inermis for the synthesis of NH4CoPO4·H2O/graphene oxide nanocomposite sensor material for ultrasensitive dopamine detection
AU - V. Kavitha
AU - G. Lakshmi Priya
PY - 2026
DA - 2026/10/16
JO - RSC advances
DO - 10.1039/d6ra09550j
UR - https://europepmc.org/article/PMC/PMC13673524
AB - A green and environment-friendly approach to bio-inspired synthesis of ammonium cobalt phosphate hydrate/graphene oxide (NH4CoPO4·H2O/GO(G)) nanocomposite was developed using the leaf extract of Lawsonia inermis as a natural reducing agent and stabilizer. To enhance the electrical conductivity and electrochemical functionality, graphene oxide (GO) was introduced into the composite, which was prepared using a modified Hummer's method from coconut shell waste. The XRD analysis confirmed the successful synthesis of the biomass-derived GO(G) and NH4CoPO4·H2O/GO(G) nanocomposite. Comprehensive characterization using field-emission scanning electron microscopy (FE-SEM), XRD, UV-visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) provided information on the structural, morphological, optical, vibrational, and chemical-state characteristics of the synthesized material. The NH4CoPO4·H2O/GO(G) nanocomposite was modified on a glassy carbon electrode (GCE), and its sensing performance was evaluated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods for electrochemical dopamine (DA) detection. The modified GCE exhibited higher electrocatalytic performance for DA oxidation, and this improvement was explained by the synergistic effect between NH4CoPO4·H2O(G) and GO(G), which promotes electron transfer and thus increases the oxidation current. The sensor had a linear response to DA in the concentration range of 5–35 µM with a sensitivity of 34.097 µA µM−1 cm−2 and a detection limit of 0.28 µM under optimal conditions. The sensor also exhibited good stability, repeatability and selectivity, which further suggests the viability of green synthesized NH4CoPO4·H2O/GO(G) nanocomposite as a green electrode material for electrochemical DA sensing applications.
SN - 2046-2069
ER -