# Rapid Point-of-Care Assessment of Paracetamol Intoxication via an Integrated Electrochemical–Colorimetric Method

## TL;DR

This paper introduces a new point-of-care method to quickly detect and measure paracetamol levels in blood, helping assess poisoning cases more effectively.

## Contribution

The novel integrated electrochemical-colorimetric method enables rapid and accurate detection of paracetamol in human serum with high selectivity and reproducibility.

## Key findings

- The method achieves a wide linear range (4.5 to 1000 mg L–1) and a detection limit of 1.2 mg L–1.
- The method demonstrates high reproducibility with RSDs below 2.0% and reliable performance in real human serum samples.
- The dual confirmation approach using colorimetric and electrochemical techniques ensures accurate and selective paracetamol detection.

## Abstract

This work addresses
the detection and quantification of paracetamol
(PAR) in human serum using a point-of-care approach, an essential
assessment for intoxication cases in clinical analysis. Electrochemical
and colorimetric methods have been widely reported for simple and
fast determination of PAR in biological samples. However, most of
these previous portable methods have neglected some aspects for a
real-world clinical application of PAR intoxication, such as its toxic
concentration range and a proper interference study in biological
matrices. To fill this gap, we introduce a novel integrated sensing
approach, combining colorimetric and electrochemical techniques for
determining PAR. In contrast to other sensors, this work employs a
simple screen-printed graphite electrode (SPE-Gr) combined with a
colorimetric reagent (CR) for the rapid and selective detection of
PAR in human serum. Analysis occurs via dual confirmation: after reaction
between PAR and CR, first a color change can indicate intoxication
levels, and the generated product is subsequently accurately quantified
by square-wave adsorptive stripping voltammetry using a SPE-Gr. A
wide linear range (4.5 to 1000 mg L–1) for determining
PAR was obtained, with a limit of detection (1.2 mg L–1), covering its therapeutic and toxic concentrations for assessment
of intoxication cases. High reproducibility was demonstrated by low
relative standard deviations (RSDs < 2.0%) and consistent responses
obtained with different disposable SPEs-Gr (n = 3).
Analysis in real human serum with a comprehensive interference study
showed a high selectivity and reliability of the proposed method for
PAR detection in biological samples. Therefore, our combined electrochemical-colorimetric
method provides a suitable point-of-care sensor for PAR determination,
enabling a prompt and straightforward diagnosis to reduce mortality
in intoxication cases.