Utilization of unmodified gold nanoparticles in colorimetric detection

Abstract

This review begins with an overview of the appealing properties and various applications of gold nanoparticles, and briefly summarizes recent advances in using unmodified gold nanoparticles to detect different kinds of targets including nucleic acids, proteins, metal ions and small organic molecules. The key point to the unmodified gold nanoparticle-based visual detection assay is to control dispersion and aggregation of colloidal nanoparticles by targets of interest, which usually relies on affinities between gold nanoparticles and targets. The degree of dispersion or aggregation can be visualized through the change of the solution color or the precipitation of nanoparticles from the solution. Thus, the existence of the target molecules can be translated into optical signals and monitored by the naked eye conveniently. Finally, some future prospects of this research field are given. gold nanoparticles, colorimetric detection, biosensor

Synthesis, characterization and catalytic performance of SAPO‐34 molecular sieves for methanol‐to‐olefin (MTO) reaction

“…to the crystallization time 21. He et al 22 analyzed the surface acidities of the SAPO‐34 molecular sieve with IR and NH 3 ‐TPD. The results showed that the Brønsted acidic centers are the main sources of the acidity of the molecular sieve.…”

Quantitative determination of ametryn in river water using surface-enhanced Raman spectroscopy coupled with an advanced chemometric model

“…1-6, 10-12, [16][17][18][22][23][24][25][26][27] and test set 1 (No. 7-9, [13][14][15][19][20][21]. Another 27 samples prepared with water from the Xiangjiang River were partitioned into calibration set 2 (No.…”

“…Some previous studies [20,21] have shown that the nitrogen-rich melamine have excellent binding capability to AuNPs. There is a strong interaction between AuNPs and melamine with three exocyclic amino groups and three-nitrogen hybrid ring, which can decrease the stability of citrate-stabilized AuNPs against the aggregation.…”

Is a Stop Solution Necessary for Metal Nanoparticles Aggregation-based Colorimetric Assays?

“…In addition, NaCl is sometimes used for assisting aggregation reactions to adjust the detection sensitivity and dynamic range to a desired concentration range [6,7]. As well as, unmodi ed MNPs-based colorimetric biosensors use NaCl at relatively high concentration to distinguish folded and unfolded ssDNA, [1,8,9]. Since at high ionic strengths, the time course of the MNPs aggregation is much faster, usually data with large errors is obtained.…”