Photoelectrochemical biosensor for histone acetyltransferase detection based on ZnO quantum dots inhibited photoactivity of BiOI nanoflower

Histone acetylation is a very important post-transcriptional modification, which is catalyzed by histone acetyltransferase with acetyl group donor of acetyl coenzyme A (Ac-CoA). Abnormal histone acetylation is associated with many diseases, so it is important to develop a sensitive and efficient method for detecting histone acetyltransferase (HAT). In this paper, a simple and sensitive photoelectrochemical biosensor was established for indirect detection of HAT using the acetylation reaction by-product of coenzyme A (CoA) as target molecule. To construct the biosensor, BiOI nanoflower was employed as photoactive material, Fe 3 O 4 -NH 2 and 3-maleimidopropionic acid were used as “bridge” reagents for immobilizing CoA, and ZnO quantum dots were adopted as photocurrent inhibitor. Under optimal experimental conditions, the photocurrent decreased with changing HAT concentration from 0.01 to 500 nM. The linear relationship between the photocurrent and the logarithm value of HAT concentration can be constructed with this concentration range and the detection limit was 3 pM (S/N = 3). The sensor has excellent detection specificity, good stability and reproducibility. Based on the current situation of serious antibiotic contamination, the effect of antibiotics on HAT activity was investigated using this photoelectrochemical biosensor.