# Paper-Based Microfluidics Platform for Enhanced On-Site Electrochemical Detection of Manganese in Water

## TL;DR

A low-cost paper-based system detects manganese in water efficiently, enabling on-site pollution monitoring.

## Contribution

Combines paper microfluidics with screen-printed electrodes for portable, sensitive manganese detection.

## Key findings

- The platform achieved a detection limit of 0.69 μg L–1 for Mn(II).
- The sensor showed excellent agreement with standard ICP-OES methods in real samples.
- The system is sustainable, portable, and suitable for detecting other pollutants.

## Abstract

Manganese pollution in water has severe toxic effects
on biological
organisms, including humans. Early detection is crucial to apply timely
corrective measures and prevent irreversible consequences. Standard
monitoring methods are expensive, time-consuming, and difficult to
implement in resource-limited settings, leading to inefficient pollution
remediation. The low cost and small size of screen-printed electrodes
make them well-suited for on-site analysis but require flow conditions
for sensitive results, making them difficult to implement in real-world
scenarios. To address this challenge, we present the use of paper
microfluidics in combination with screen-printed carbon electrodes
for the electrochemical detection of manganese in water. Capillary-driven
flow using paper microfluidics provided a practical fluid delivery
method for on-site electroanalysis, which was compared to conventional
flow methods, i.e., batch setups and flow cells, to demonstrate fitness
for purpose. The sensing platform showed a linear response to Mn­(II)
up to 200 μg L–1, with a detection limit of
0.69 μg L–1, well below the WHO guideline
value. The response of the sensor was also analyzed in the presence
of potentially interfering metals, and validated in real samples,
showing excellent agreement with a standard inductively coupled plasma
optical emission spectroscopy method. This approach, inducing flow
with paper, is more sustainable, simple, portable, and cost-effective
compared to the conventional methods, resulting in a setup with high
applicability toward the detection of other pollutants such as metals,
PFAS, and pharmaceuticals.