A Gold Nanoclusters Film Supported on Polydopamine for Fluorescent Sensing of Free Bilirubin

Abstract

Serum bilirubin is an important biomarker for the diagnosis of various types of liver diseases and blood disorders. A polydopamine/gold nanoclusters composite film was fabricated for the fluorescent sensing of free bilirubin. Bovine serum albumin (BSA)-stabilized gold nanoclusters (AuNCs) were used as probes for biorecognition. The polydopamine film was utilized as an adhesion layer for immobilization of AuNCs. When the composite film was exposed to free bilirubin, due to the complex that was formed between BSA and free bilirubin, the fluorescence intensity of the composite film was gradually weakened as the bilirubin concentration increased. The fluorescence quenching ratio (F0/F) was linearly proportional to free bilirubin over the concentration range of 0.8~50 μmol/L with a limit of detection of 0.61 ± 0.12 μmol/L (S/N = 3). The response was quick, the film was recyclable, and common ingredients in human serum did not interfere with the detection of free bilirubin.

Langmuir and Langmuir–Blodgett Films of Gold and Silver Nanoparticles

“…Moreover, while the optical properties of larger NPs are dominated by the SPR based on quasi-continuous electronic energy levels, clusters exhibit more molecular-like behavior with their distinct absorption features originating from discrete electronic energy levels. , This has led to a number of potential optical applications, which can be further enhanced through their collective action in close-packed 2D assemblies. With some Au cluster systems already demonstrating their usefulness in prospective applications, for example, as glucose sensors or in liver disease detection, we believe that many of them as well as countless new platforms would benefit highly from being deposited as LB films which offer low production costs, high coverage, and high durability.…”

“…95,96 This has led to a number of potential optical applications, which can be further enhanced through their collective action in close-packed 2D assemblies. With some Au cluster systems already demonstrating their usefulness in prospective applications, for example, as glucose sensors 97 or in liver disease detection, 98 we believe that many of them as well as countless new platforms would benefit highly from being deposited as LB films which offer low production costs, high coverage, and high durability. At the same time, a number of fundamental properties of noble metal LB films that are still not clear after decades of studying large NPs could be elucidated with the help of atomically precise clusters.…”

Biomarker sensing platforms based on fluorescent metal nanoclusters

“…One of the main mechanisms of detection is based on the NC emission quenching effect when the biosensor is linked to the target biomarker. Some examples include the detection of creatinine in kidney functional activity disorders, 88 using GSH-CuNCs that are destabilized in the presence of creatinine; 89 the detection of bilirubin in the diagnosis of liver diseases using BSA stabilized AuNCs that disassemble when the complex BSA-bilirubin is formed; 90 or the detection of miRNA 145 using a AgNC-DNA biosensor in the diagnosis of multiple sclerosis (MS) based on the hybridizing strategy already discussed. Halawa et al 91 used an eco-friendly approach to develop GSH-capped AuNCs initiated using samarium (Sm 3+ ) lanthanides for the first time.…”