Development of Gold Nanoparticle based Colorimetric Monkeypox Biosensors Suitable for Point of Care (POC) Analysis

Practical colorimetric biosensors were developed for the detections of A29 and A27L proteins which were defined as Monkeypox virus (MPXV) and smallpox target proteins. For this purpose, gold nanoparticles (AuNPs) were synthesized and used to detect specific interaction between heparan sulphate (HS) receptor and A29 or A27L target proteins. This study is the first colorimetric biosensor that was based on the interaction of HS and A29 or A27L protein. In this work first, HS was labeled with AuNPs. When AuNPs labeled HS was incubated with A29 or A27L protein structure, these proteins specifically bounded to HS. Next, obtained AuNP/HS‐A29 or AuNP/HS‐A27L structures began to aggregate, and then difference in absorbance value of AuNP at 530 nm occurred. Absorbance differences at 530 nm were monitored spectroscopically. After experimental parameters were optimized, analytical characteristics of developed biosensors were investigated. As a result, the limit of detection was calculated as 7.93 ng.mL−1 and 6.09 ng.mL−1for A29 protein and A27L, respectively. The relative standard deviation were calculated as 1.97 % and 5.72 % for 25 ng.mL−1 A29 and 12.5 ng.mL−1 A27, respectively. Sample application studies were also performed with the standard addition of A29 and A27L proteins to real serum samples taken from healthy individuals. As a result, very promising results were obtained. Practical colorimetric biosensors were developed for the detections of A29 and A27L proteins which were defined as Monkeypox virus and smallpox target proteins. Gold nanoparticles (AuNPs) functionalized with heparan sulphate (HS), interacted with and A29 or A27L target proteins. The difference in absorbance value of AuNP that was occurred due to aggregation of AuNP/HS‐A29 or AuNP/HS‐A27L structures were followed.