# Design of Electrochemical Sensor Based on Pumpkin Peel Biomass-Derived Carbon Black-Modified Electrode for the Detection of Lead Ions

## TL;DR

This paper presents a low-cost, eco-friendly electrochemical sensor using carbon derived from pumpkin peels to detect trace amounts of lead ions in water.

## Contribution

The novel contribution is the use of pumpkin peel-derived carbon black as a sustainable electrode modifier for lead ion detection.

## Key findings

- The CB650-GCE sensor showed a detection limit of 0.19 µM and quantification limit of 0.58 µM for Pb2+.
- The sensor demonstrated good selectivity and satisfactory recovery in tap and seawater samples.
- The CB material exhibited a mesoporous structure and high surface area, enhancing electrochemical performance.

## Abstract

This study reports a sustainable and experimentally simple electrochemical platform for monitoring trace Pb2+ using pumpkin peel-derived carbon black (CB) as a modifier on a Nafion-coated glassy carbon electrode (CB/Nafion-GCE). Agricultural waste pumpkin peels were converted into CB, offering a low-cost and environmentally friendly sensing material. CB produced at 650 °C was systematically characterized by SEM, TEM, EDX, XRD, FT-IR, and BET, revealing a mesoporous structure, high surface area, and partial graphitization that enlarged the electroactive area and reduced charge transfer resistance relative to the bare GCE. Under optimized square wave anodic stripping voltammetry (SWASV) conditions, the glassy carbon electrode modified with CB produced at 650 °C (CB650-GCE) exhibited a well-defined linear response towards Pb2+ with a limit of detection of approximately 0.19 µM and a limit of quantification of about 0.58 µM, together with good selectivity against common coexisting metal ions. The sensor also achieved satisfactory recoveries in tap and seawater samples, demonstrating its potential as a practical, green analytical tool for routine lead surveillance in environmental waters.