Multicolor Biosensor for Trypsin Detection Based on the Regulation of the Peroxidase Activity of Bovine Serum Albumin-Coated Gold Nanoclusters and Etching of Gold Nanobipyramids.

The detection of trypsin is significantly important for both clinical diagnosis and disease treatment. In this study, an innovative multicolor sensor for trypsin detection has been established based on the regulation of the peroxidase activity of bovine serum albumin-coated gold nanoclusters (BSA-Au NCs) and efficient etching of gold nanobipyramids (Au NBPs). BSA-Au NCs have slight peroxidase enzyme activity and can catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to generate TMB, while trypsin can hydrolyze BSA ligands on the surface of BSA-Au NCs, thus exposing more catalytic active sites of BSA-Au NCs and resulting in the enhancement of the peroxidase activity of BSA-Au NCs, hence more TMB is generated.

Electrochemiluminescence biosensor for DNA adenine methylation methyltransferase based on CRISPR/Cas12a trans-cleavage-induced dual signal enhancement.

In this work, an electrochemiluminescence (ECL) biosensor with dual signal enhancement was constructed and used for DNA adenine methylation methyltransferase (Dam MTase) detection. At present of Dam MTase, restriction endonuclease (DPnI) cleaves hairpin DNA (HP) and releases the HP stem end as a single strand that can activate CRISPR/Cas12a trans-cleavage activity. Assisted by trans-cleavage, the distance between the signal quenching factor ferrocene (Fc) and the ECL signal unit increased, and the repulsion between the signal unit and the Indium Tin Oxides (ITO) electrode decreased.