Bioaffinity-based assay for the sensitive detection and discrimination of sweat aimed at forensic applications

Sweat is a well-known piece of biological evidence that is actually used much less than expected. Biological samples are important because their components can often provide some type of information about a person-of-interest. Sweat, in particular, is important because of its DNA content which can be extracted and analyzed to provide information that can be imperative to a criminal investigation. While it is a very important source of forensic information, the methods for detection and discrimination of sweat are limited, causing it to be overlooked during evidence collection. This manuscript presents a biocatalytic method for sweat detection that utilizes an enzyme cascade system that has the capability to detect trace amounts of sweat and distinguish it from saliva, even after the sample has dried. The results show the initial calibration studies performed to insure that the cascade performs well using both mimicked and authentic sweat samples which have components that could negatively affect the enzymes needed for the analysis. The method presented here also has the potential to be adapted for on-site analysis. The initial results of the development of a sweat-sensitive strip are shown here.