Determination of bilirubin by adsorptive stripping voltammetry

Water-soluble MoS2 quantum dots as effective fluorescence probe for the determination of bilirubin in human fluids

Bilirubin is an important biomarker in the diagnosis and prognosis of patients with liver disorders. Herein, we report a simple, rapid, sensitive and selective quantitative determination of bilirubin using molybdenum disulfide quantum dots (MoS₂ QDs) as a probe. The MoS₂ QDs were synthesized through a hydrothermal route by using sodium molybdate and cysteine as the starting materials. The obtained MoS₂ QDs exhibits strong luminescence property and excellent stability. The HR-TEM image shows that the size of the prepared MoS₂ QDs was 2.4 nm with a spherical morphology. The MoS₂ QDs emit intense blue photoluminescence (with excitation/emission peaks at 310/392 nm) under UV light and the fluorescence of MoS₂ QDs was drastically quenched by the addition of bilirubin. The Förster resonance energy transfer (FRET) and inner filter effect (IFE) between MoS₂ QDs and bilirubin resulted in the fluorescence quenching of MoS₂ QDs. The present method demonstrated high sensitivity towards bilirubin with the limit of detection (LOD) of 2.1 nM (S/N = 3). The MoS₂ QDs probe showed remarkable selectivity to bilirubin over other possible interferences. Moreover, the present fluorophore was successfully utilized for the detection of bilirubin in human serum and urine samples. QDs based fluorescence probe for the recognition of bilirubin is reported for the first time.

A recyclable post-synthetically modified Al(iii) based metal–organic framework for fast and selective fluorogenic recognition of bilirubin in human biofluids

The ultra-fast, highly sensitive and selective sensing features of bilirubin in human biofluids by a post-synthetically modified Al(iii) MOF are presented.

Electrochemical biosensor with graphene oxide nanoparticles and polypyrrole interface for the detection of bilirubin

A bilirubin biosensor was fabricated by immobilization of bilirubin oxidase (BOx) on a graphene oxide nanoparticle (GONP) decorated polypyrrole (Ppy) layer electrochemically deposited onto a fluorine doped tin oxide (FTO) glass plate.

Non-enzymatic detection of bilirubin based on a graphene–polystyrene sulfonate composite

A reduced graphene oxide–poly styrene sulfonate (RGO–PSS) modified GC electrode for the detection of bilirubin.

Study of Adsorption Behavior of Bilirubin on Human-Albumin Monolayer Using a Quartz Crystal Microbalance

The quartz crystal microbalance was employed to study the adsorption behavior of bilirubin on human-albumin layer, which was chemically bound to the self-assembled monolayer of 4-aminothiophenol on the surface of a gold electrode of the crystal via glutaraldehyde. A long-time adsorption process of bilirubin that took place on a human-albumin-modified surface was observed, and the adsorption kinetic parameters were estimated from the in situ frequency measurements. The amount of adsorbed bilirubin increased with increasing of both hydrogen ions and bilirubin concentration and was larger than that estimated based on the conclusion that there are two affinity sites for bilirubin per albumin molecule. With the present method, the displacement of bilirubin from an albumin layer caused by aspirin was also examined. QCM measurement provides a facile method for in situ monitoring of the adsorption/desorption of bilirubin on proteins layers.

Adsorptive stripping voltammetry applied to drug analysis: a powerful tool

A brief review of the principles and instrumentation of adsorptive stripping voltammetry is presented and the advantages of the method are described. As for many highly sensitive techniques applied to the analysis of complex media, severe interferences may occur. Different approaches can be used to circumvent these problems, exemplified by several applications in biological fluids. The application of modified electrodes to enhance selectivity is discussed.