# Enhanced Electrochemical Detection of Lead Ions Using Schiff Base/MoS2 Modified Screen-Printed Electrodes

## TL;DR

A new sensor using modified electrodes detects lead ions in water efficiently and affordably.

## Contribution

A covalent interface of MoS2 and Schiff base enhances Pb2+ detection with high sensitivity and selectivity.

## Key findings

- The sensor achieves a sensitivity of 220.344 μA μM–1 cm–2 for Pb2+ detection.
- The limit of detection is 0.267 μM with a linear range of 1–5 μM.
- The sensor performs reliably in tap water samples with good reproducibility.

## Abstract

Environmental contamination by heavy metals (HMs) remains
a critical
concern; among them, Pb2+ is distinguished by its toxicity,
bioaccumulation, and persistence. Here, we present disposable, noble-metal-free
screen-printed carbon electrodes (SPCEs) functionalized with MoS2 nanosheets covalently conjugated to newly synthesized Schiff
bases (SB1, SB2) via a monochloroacetic-acid linker, affording a chemically
defined MoS2–SB interface for enhanced Pb2+ sensing in water. Using square-wave anodic stripping voltammetry
(SWASV) under optimized conditions in PBS (pH 4.0), the MoS2@SB2/SPCE exhibits markedly higher currents than both bare and other
modified electrodes. The sensor achieves an area-normalized sensitivity
of 220.344 μA μM–1 cm–2, a limit of detection of 0.267 μM, and a primary linear range
of 1–5 μM for Pb2+. This covalent interfacial
design couples the high surface area and conductivity of MoS2 with SB2 driven chelation, yielding good selectivity, device-to-device
reproducibility, and reliable performance in tap water samples. Our
results outline a viable path for the low-cost and on-site monitoring
of lead ions in complex water matrices.