Eco-friendly sensor developed at INL enables rapid detection of pharmaceutical contaminants in water

July 31, 2025

Pharmaceutical waste in water sources is becoming a growing environmental concern. Among the most common pollutants are paracetamol and 4-aminophenol, a related compound that can appear as a contaminant or breakdown product. These substances persist in urban wastewater and surface waters, potentially harming aquatic ecosystems and human health. Detecting them accurately and efficiently is crucial for environmental protection and risk management.

Researchers at INL from Espiña’s research group have designed an innovative electrochemical sensor that can simultaneously detect both pharmaceuticals at very low concentrations. The sensor uses carbon screen-printed electrodes modified with specially functionalised carbon nanofibers, which enhance sensitivity and selectivity. This study published in the journal Sensing and Bio-Sensing Research, describes a solution for portable, cost-effective, and environmentally friendly tool for water quality monitoring.

Traditional methods for identifying pharmaceutical contaminants often rely on complex laboratory techniques such as chromatography and spectrometry. While highly precise, these require expensive equipment, trained personnel, and time-consuming sample preparation, limiting their use for routine or on-site testing. In contrast, electrochemical sensors like the one developed by the INL team led by Raquel Queirós, provide rapid, real-time results with minimal costs.

The research team compared different transducer materials, finding that carbon-based ones performed better than gold electrodes for the specific detection of these contaminants. Raquel Queirós explains that “by functionalising carbon electrodes with modified carbon nanofibers, we increased the surface area and enhanced electron transfer, facilitating stronger interactions with the analytes and improving sensor performance.”

Tests conducted with real freshwater samples showed that the sensor maintains its performance even in complex environments with potentially interfering substances. “Beyond detection, the sensor also proved useful in tracking the degradation of paracetamol during water treatment processes, highlighting its potential for continuous monitoring in practical applications,” Raquel Queirós adds.

This development represents a significant step forward in environmental sensing technology. By combining advanced nanomaterials with user-friendly and cost-efficient devices, INL’s sensor offers a promising solution for tackling pharmaceutical pollution in water, supporting efforts to safeguard ecosystems and public health.