All Projects Hardware · Electrochemistry · Signal Processing

Low-Cost Potentiostat for Heavy Metal Detection

A portable and affordable potentiostat for detecting heavy metal ions in water using Square Wave Voltammetry, developed at IIT Hyderabad & Kathmandu University.

Sep 2023 – May 2024 IIT Hyderabad · Kathmandu University Published Research

Project Snapshot

Project Type

Hardware Dev · Electrochemistry · Signal Processing

Core Technique

Square Wave Voltammetry (SWV)

Target Analytes

As · Cr · Pb · Cd · Hg

Key Outcome

Comparable to commercial Sensit Smart device

My Role

Research Intern

Supervisor

Prof. Amit Acharyya

Project Overview

The Challenge

Heavy metal contamination in water bodies poses a severe global public health and environmental threat. Existing detection methods often rely on expensive, bulky laboratory equipment, limiting their accessibility for widespread, real-time monitoring in developing regions. There is a critical need for low-cost, portable, and accurate solutions for on-site heavy metal ion detection.

Our Solution

This project focuses on the design and development of a low-cost, portable potentiostat specifically engineered for the detection of heavy metal ions (Arsenic, Chromium, Lead, Cadmium, and Mercury) in water. Utilizing Square Wave Voltammetry (SWV), the system combines custom hardware with a novel data processing algorithm and user-friendly mobile and web applications to provide an accessible and efficient water quality monitoring solution.

Approach & Methodology

Potentiostat Hardware Design

Engineered a custom potentiostat circuit capable of performing Square Wave Voltammetry. Designed for affordability, portability, and robust signal acquisition for accurate electrochemical measurements.

Advanced Signal Processing

Developed a novel algorithm incorporating windowing and linear extrapolation techniques to precisely identify and quantify specific heavy metal ions by analyzing their distinct electrochemical SWV signatures.

Multi-Platform User Interface

Created intuitive mobile (Flutter) and web (Streamlit) applications enabling real-time data visualization, historical tracking, and simplified interaction with the potentiostat device.

Real-time Alert System

Implemented a Telegram-based notification system providing immediate alerts upon detection of toxic heavy metal ion concentrations, ensuring timely intervention.

Validation & Benchmarking

Rigorously validated the custom potentiostat's performance against commercial devices (Sensit Smart), demonstrating comparable accuracy. Validated using ADUCM evaluation board and Electrochemical Impedance Spectroscopy (EIS).

Key Results & Visualizations

SWV plot comparison between custom potentiostat and Sensit Smart
Figure 1: Comparison of SWV plots from the custom potentiostat vs. commercial Sensit Smart device, demonstrating comparable performance.
Web application for potentiostat data visualization and alerts
Figure 2: Developed web application providing real-time data visualization and alerts for detected heavy metal ions.

Technologies Used

Square Wave Voltammetry (SWV) Python MATLAB Flutter (Mobile App) Streamlit (Web App) ESP32 (Microcontroller) LTSpice (Circuit Simulation) Electrochemical Impedance Spectroscopy (EIS)

Lessons Learned & Challenges

Precision Analog Circuit Design

Ensuring stability and accuracy of the potentiostat's analog front-end was critical, requiring careful component selection and noise reduction techniques.

Signal-to-Noise Ratio Optimization

Optimizing SNR in electrochemical measurements at low ion concentrations was crucial for achieving reliable detection limits.

Algorithm Robustness

Developing a robust windowing and linear extrapolation algorithm that accurately identifies and quantifies ions across varying concentrations required extensive data analysis and iterative refinement.

Hardware-Software Integration

Seamless integration between custom hardware, ESP32, and mobile/web applications presented challenges in data transfer protocols and real-time synchronization.

Cost vs. Performance Balance

Striking the right balance between minimizing hardware cost and maintaining high performance ensures accessibility without compromising accuracy — a key insight of this project.

Future Goals

Future work aims to enhance capabilities for simultaneous detection of multiple heavy metal ions (Cr, Pb, Cd, Hg) by exploring a multi-channel chip array design. We also plan to further automate data integration and analysis processes, moving towards a fully autonomous water quality monitoring system for continuous environmental surveillance.

Read the Work

Published Research

This work has been published. Read the full thesis on ResearchGate.

Read Full Thesis All Projects