# Engineered PVA Hydrogel as a Universal Platform for Developing Stable and Sensitive Microbial BOD-Biosensors

## TL;DR

Scientists developed a new hydrogel platform that improves microbial biosensors for measuring water quality by detecting oxygen demand more effectively.

## Contribution

A novel PVA hydrogel modification method using UV and Ce4+ treatment creates a stable platform for sensitive microbial BOD biosensors.

## Key findings

- The FC+NR–B. adeninivorans–PVA–Ce4+ system showed high sensitivity with a linear range of 0.1–3.81 mgO2/dm3.
- The biosensor had an operational stability of up to 37 days and strong correlation with standard BOD5 in wastewater testing.
- The radical modification method is simple and effective for creating stable and sensitive biosensors for environmental monitoring.

## Abstract

Polyvinyl alcohol (PVA) hydrogels modified through radical polymerization under UV irradiation and Ce4+ ion treatment were investigated as a potential platform for developing highly sensitive biosensors for rapid biochemical oxygen demand analysis in water. These modifications enhance PVA physicochemical properties, including mechanical strength, stability, and biocompatibility, making it promising for immobilizing microorganisms in bioanalytical systems. A dual-mediator biosensor system using ferrocene (FC) and neutral red (NR) was developed with yeast Blastobotrys adeninivorans immobilized in modified PVA. The FC+NR–B. adeninivorans–PVA–Ce4+ system exhibited high sensitivity (linear range of 0.1–3.81 mgO2/dm3), selectivity, and operational stability (up to 37 days service life), outperforming existing analogs. Testing with wastewater confirmed strong correlation with standard BOD5, highlighting the potential for monitoring water quality. The described radical modification method is a simple and effective approach for creating sensitive and stable biosensors. It opens up new possibilities for environmental monitoring technology.