Surfactant mediated electrodeposition of Cu-Ag nanostructures on pencil graphite electrodes for amperometric detection of nitrate

초록

A promising approach to enhance the electrocatalytic sensor performance is by tailoring nanoscale morphology using surfactant-assisted electrodeposition. In this study, we demonstrate a novel, cost-effective and highly sensitive amperometric sensor for nitrate quantification in water using Cu-Ag bimetallic nanostructures. Copper was initially electrodeposited using different surfactants acting as soft templates and subsequently followed by galvanic replacement for silver modification. The surfactant-directed growth led to tunable copper morphologies-dendritic structures with SDS, rod-like formations with CTAB, and discrete grains with TX-100, confirmed through scanning electron microscopy. The anionic SDS-derived copper nanostructures enabled superior nitrate sensing performance upon silver integration, underscoring the significance of morphology in catalyst design. Under optimised conditions, the sensor exhibited a low detection limit of 0.13 mu M and a sensitivity of 3.39 mu A/mu M/cm2 for nitrate analysis. Practical applicability was demonstrated using beetroot juice as a real sample, where the nitrate concentration determined (1.28 mM) was in close agreement with the standard chromatography results. Moreover, the sensor's swift preparation time and prompt detection render it as a potential tool for nitrate monitoring in industrial and environmental contexts.

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