Gold Nanoparticle-Based Colorimetric Assay for Selenium Detection via Hydride Generation

Abstract

Gold nanoparticles (AuNPs)-based colorimetric assays are of particular interest since molecular events can be easily read out with the color changes of AuNPs by the naked eye. However, the molecular recognitions occur almost exclusively in the liquid phase (i.e., the interaction between target analytes and AuNPs is always proceeded in the presence of the sample matrix). Since the aggregation of the unmodified AuNPs is prone to be influenced by the ionic strength of the solution, sample matrix will cause undesirable interference. Here, we proposed a new type of AuNP-based colorimetric assay, in which target analyte selenium was first converted to its hydride chemical vapor (HSe) and then delivered into the solution of AuNPs to induce color change. Therefore, sample matrix (for example, high salinity) were eliminated, leading to excellent selectivity. With the aid of hydride generation, the proposed method offered a detection limit of 0.05 μM with UV-vis detection and 1 μM with the naked eye. Successful application of this method for selenium detection in biological and environmental samples was demonstrated.

Green and Facile Synthesis of Highly Stable Gold Nanoparticles via Hyperbranched Polymer In-Situ Reduction and Their Application in Ag+ Detection and Separation

“…In recent years, AuNPs are the most widely studied colorimetric sensors of Ag + detection due to their high extinction coefficients and sensitive surface plasmon resonance (SPR) sensing characteristics in the visible region [7,8,9,10]. Many methods using citrate reduction [11], hydrazine reduction [12], sodium borohydride reduction [13], and solvent extraction reduction [14] have been developed to prepare AuNPs. However, these small-molecule reducing agents are all highly toxic or unsafe.…”

Rapid and PCR-free DNA Detection by Nanoaggregation-Enhanced Chemiluminescence

“… 23 . There are mainly two driven forces for the aggregation of AuNPs to happen: one is the target-guided assembling that brings AuNPs close to each other (cross-linking); and another is salt-induced deterioration of the electrostatic repulsion forces between citrate-stabilized AuNPs (non-cross-linking) 3 . With the use of LSPR spectroscopy, Abbas et al .…”

“…Unique chemical and physical properties of AuNPs include high extinction coefficients in the visible region, alterable surface plasmon resonance (SPR) absorption, simple preparation, and easy functionalization. Therefore, AuNPs-based assays offer broad analytical capabilities and have already found multiple applications in detection of ions 2 , 3 , small molecules 4 , 5 , proteins 6 , 7 , DNA 8 , 9 , and cancerous cells 10 , 11 . Target hybridization with a labeled oligonucleotide probe is one the most widely used methods for detection of sequence-specific DNA nowadays 12 , 13 .…”

Latest advances in combining gold nanomaterials with physical stimuli towards new responsive therapeutic and diagnostic strategies

“…Thus, the simplest implementation of LSPR sensing is the use of AuNMs as a functional component of colorimetric assays both in liquid (homophase methods) and solid (dot immunoassay and immunochromatography) phase [1]. In these assays, AuNMs are conjugated with a bioactive moiety capable of binding with high-affinity specific analytes present in a solution [157,158], such as biomolecules (e.g., proteins [159] or toxins [160]), small molecules (oligonucleotides [161]), ions (e.g., selenium [162]), or diseased cells (e.g., acute leukemia cells [163]). AuNMs-based optical sensors can also be used to detect specific antigens within the cellular compartments [164,165].…”