Cost-Effective Foam-Based Colorimetric Sensor for Roadside Testing of Alcohol in Undiluted Saliva

Abstract

A novel foam-based colorimetric alcohol sensor was developed for the detection of alcohol in saliva. Detection was based on the color change of a potassium dichromate-sulfuric acid solution absorbed by melamine foam. In the presence of alcohol, the orange colorimetric sensor changed color to brown, green and, ultimately, blue, depending on the concentration of alcohol in the sample. The response of the proposed sensor toward alcohol was linear from 0.10 to 2.5% v/v. The limit of detection was 0.03% v/v. Alcohol concentration could be determined using the naked eye in the range of 0.00 to 10% v/v. The developed alcohol sensor presented good operational accuracy (RSD = 0.30–1.90%, n = 8) and good stability for 21 days when stored at 25 °C and 75 days when stored at 4 °C. The results of alcohol detection with the developed sensor showed no significant difference from the results of spectrophotometric detection at a 95% confidence level (p > 0.05). The sensor was easy to use, small, inexpensive and portable, enabling drivers to accurately measure their own blood alcohol level and providing convenient speed in forensic applications.

Electrochemical paper-based antigen sensing platform using plant-derived monoclonal antibody for detecting SARS-CoV-2

“…The selectivity for saliva application was firstly examined. The proposed immunosensor was tested with various interferences that can be possibly found in saliva, including glucose, ascorbic acid (AA) and human serum albumin (HSA) [ 43 , 44 ]. All examined interferences were prepared by mixing with the RBD (0.5 μg/mL) in the concentration that was 100 times higher than target RBD.…”

Alcohol Detection Using Automation

“…A novel method with foam-based colorimetric alcohol sensor is proposed in (11). Potassium dichromate in sulfuric acid was used as a colorimetric reagent for the detection of alcohol in undiluted saliva.…”