2‐(N‐Morpholino)ethanesulphonic acid mediated facile and rapid one‐pot synthesis of gold nanoparticles and its application for colorimetric detection of heparin in human serum

Abstract

A facile and rapid method for one‐pot synthesis of gold nanoparticles (AuNPs) has been developed. It employed 2‐(N‐morpholino)ethanesulphonic acid (MES) to act as reducing agent, buffering agent, and capping ligand to perform the reduction of the gold precursor (HAuCl4) into AuNPs. The AuNPs were synthesized by a simple mixing of MES buffer (pH 6.0) and HAuCl4 solution under a vortex at room temperature, and the process was completed within 1 min, which not only significantly simplifies the preparation procedure without heating or cooling but also greatly shortens the reaction time. Moreover, a novel colorimetric approach for sensitive detection of heparin was fabricated based on the prepared AuNPs. The detection limit was determined to be 3.1 μg/ml (i.e., 0.465 U/ml) with a linear response range of 3.25–130 μg/ml. Additionally, the sensor was also successfully applied for the detection of heparin in human blood serum samples, demonstrating its potential applicability for disease diagnosis in the future.