Non-Enzymatically Colorimetric Bilirubin Sensing Based on the Catalytic Structure Disruption of Gold Nanocages

Abstract

As an essential indicator of liver function, bilirubin is of great significance for clinical diagnosis. A non-enzymatic sensor has been established for sensitive bilirubin detection based on the bilirubin oxidation catalyzed by unlabeled gold nanocages (GNCs). GNCs with dual-localized surface plasmon resonance (LSPR) peaks were prepared by a one-pot method. One peak around 500 nm was ascribed to gold nanoparticles (AuNPs), and the other located in the near-infrared region was the typical peak of GNCs. The catalytic oxidation of bilirubin by GNCs was accompanied by the disruption of cage structure, releasing free AuNPs from the nanocage. This transformation changed the dual peak intensities in opposite trend, and made it possible to realize the colorimetric sensing of bilirubin in a ratiometric mode. The absorbance ratios showed good linearity to bilirubin concentrations in the range of 0.20~3.60 μmol/L with a detection limit of 39.35 nM (3σ, n = 3). The sensor exhibited excellent selectivity for bilirubin over other coexisting substances. Bilirubin in real human serum samples was detected with recoveries ranging from 94.5 to 102.6%. The method for bilirubin assay is simple, sensitive and without complex biolabeling.

Fluorescence-Based Portable Assays for Detection of Biological and Chemical Analytes

“…A few of the plasmonic NP-based tests are already available commercially, e.g., pregnancy tests and COVID test kits. Various strategies have been employed for signal amplification in colorimetric assays to achieve nanomolar to picomolar level detection, such as the detection of bilirubin using gold nanocages (LOD ~39.35 nM), or trypsin using peptide-immobilized AuNPs (LOD 0.5 nM) [138][139][140]. For further improvement of colorimetric assays to the sub-picomolar detection level, different strategies have been applied [141,142].…”

Effect of Aspect Ratio of a Gold-Nanorod-Modified Screen-Printed Carbon Electrode for Carbaryl Detection in Three Different Samples of Vegetables

“…In contrast, electrochemical methods based on a disposable screen-printed carbon electrode (SPCE) offer an excellent alternative option for onsite pesticide detection owing to their rapid, low-cost, simple operation, versatility, and high sensitivity. − Meanwhile, the employment of different shapes of gold nanoparticles via nanospheres, − nanorods, − nanocubes, − nanostars, − nanocages, − nanotriangles, − nanohexagon, − and nanobipyramids − has been widely explored to enhance its sensitivity for the purpose of sensing applications. Among these various shapes of gold nanoparticles, gold nanorods (AuNRs) have attracted considerable attention due to their anisotropic structures and high surface area that could facilitate faster electron transfer capability on the electrode surface .…”

Review—Trends on the Development of Non-Enzymatic Electrochemical Sensors Modified with Molecularly Imprinted Polymers for the Quantification of Glucose

“…In this sense, spectrophotometry, [26][27][28] chromatography, [29][30][31] electrophoresis, 32,33 fluorescence, 34,35 and chemiluminescence 36,37 have been reported as traditional analytical techniques for glucose quantification; unfortunately, these ones need sample pretreatment, sophisticated instrumentation, and the use of excessive organic solvents. 38,39 Methodologies based on electrochemistry represent a viable alternative in the quantification of glucose due to their simplicity, low-cost, rapid response, and easy implementation, overcoming the drawbacks mentioned above. 40,41 The working electrode play an important role in the electrochemical determinations, and recent proposals has been reported the use of modified sensors to increase the rate of electron transfer, and the analytical parameters (linear range, limit of detection (LOD), sensitivity, and selectivity).…”