# Highly Sensitive Detection of Chymotrypsin Using Gold Nanoclusters with Peptide Sensors

## TL;DR

A new method using gold nanoclusters and peptides detects chymotrypsin with high sensitivity, which could help diagnose pancreatic diseases.

## Contribution

A novel sensor using graphene oxide and gold nanoclusters achieves a detection limit of 2.014 pg/mL for chymotrypsin.

## Key findings

- The detection limit of chymotrypsin reached 2.014 pg/mL using the developed method.
- The method demonstrated high sensitivity compared to previous studies.
- The sensor is suitable for real sample analysis due to its potential efficacy.

## Abstract

Pancreatic function tests are used to determine the presence of chronic pancreatitis, particularly in the early stage of the disease. Chymotrypsin is an indicator of pancreatic function and is thus related to pancreatic diseases. However, these methods often require specific equipment and cannot always meet on-site analysis requirements. Consequently, a highly sensitive detection method needs to be developed. This research employed graphene oxide modified with NHS sensors and peptides (RRHFFGC: Arginine-Arginine-Histidine-Phenylalanine-Phenylalanine-Glycine-Cysteine) tagged with gold nanoclusters (Au NCs) for the detection of chymotrypsin. The N-Hydroxysuccinimide-(Polyethylene Glycol)4-Dibenzocyclooctyne (NHS-PEG4-DBCO) and graphene oxide (GO)-N3 click reaction yielded GO-NHS material, appropriate for fluorescence quenching. The peptide chain was accurately broken with the introduction of chymotrypsin, and the Au NCs were situated far from the GO-NHS surface. The detection limit was 2.014 pg/mL. The results showed that the detection method had high sensitivity in comparison with the previous studies. This method is relevant to real samples due to its potential efficacy. Therefore, it is a promising method in the biomedical field.