In Situ Enzymatic Generation of Gold Nanoparticles for Nanozymatic Label-free Detection of Acid Phosphatase

2020 ◽  
Vol 3 (9) ◽  
pp. 9462-9469
Author(s):  
Syed Rahin Ahmed ◽  
Aicheng Chen
2017 ◽  
Vol 22 (10) ◽  
pp. 1203-1210 ◽  
Author(s):  
Katrin Beeman ◽  
Jens Baumgärtner ◽  
Manuel Laubenheimer ◽  
Karlheinz Hergesell ◽  
Martin Hoffmann ◽  
...  

Mass spectrometry (MS) is known for its label-free detection of substrates and products from a variety of enzyme reactions. Recent hardware improvements have increased interest in the use of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS for high-throughput drug discovery. Despite interest in this technology, several challenges remain and must be overcome before MALDI-MS can be integrated as an automated “in-line reader” for high-throughput drug discovery. Two such hurdles include in situ sample processing and deposition, as well as integration of MALDI-MS for enzymatic screening assays that usually contain high levels of MS-incompatible components. Here we adapt our c-MET kinase assay to optimize for MALDI-MS compatibility and test its feasibility for compound screening. The pros and cons of the Echo (Labcyte) as a transfer system for in situ MALDI-MS sample preparation are discussed. We demonstrate that this method generates robust data in a 1536-grid format. We use the MALDI-MS to directly measure the ratio of c-MET substrate and phosphorylated product to acquire IC50 curves and demonstrate that the pharmacology is unaffected. The resulting IC50 values correlate well between the common label-based capillary electrophoresis and the label-free MALDI-MS detection method. We predict that label-free MALDI-MS-based high-throughput screening will become increasingly important and more widely used for drug discovery.


2017 ◽  
Vol 89 (3) ◽  
pp. 1892-1899 ◽  
Author(s):  
Zhuoliang Liu ◽  
Xingyu Luo ◽  
Zhu Li ◽  
Yan Huang ◽  
Zhou Nie ◽  
...  

2017 ◽  
Vol 321 ◽  
pp. 417-423 ◽  
Author(s):  
Abdul Ghaffar Memon ◽  
Xiaohong Zhou ◽  
Jinchuan Liu ◽  
Ruoyu Wang ◽  
Lanhua Liu ◽  
...  

2017 ◽  
Vol 240 ◽  
pp. 651-656 ◽  
Author(s):  
Pengjuan Ni ◽  
Yujing Sun ◽  
Shu Jiang ◽  
Wangdong Lu ◽  
Yilin Wang ◽  
...  

Dengue virus (DENV) is a reemerging mosquito-borne disease that is endemic in more than 125 countries, affecting 200 million people per year. Screening testing has been a good attempt to minimize the impact caused by high morbity and mortality rates of DENV. In this study, a simple and disposable label-free electrochemical immunosensor based on a carbon ink graphite screen-printed electrode (SPE) one-step fabricated was developed for detection of non-structural 1 protein (NS1). The SPE surface was modified by drop casting, depositing a colloidal suspension containing amine-functionalized gold nanoparticles (AuNP-NH2). AuNPs were synthetized by a photoinduced physical method, illuminating preformed gold seeds with a light-emitting diode (LED,) at blue region, by using the polyethyleneimine (NH2) as reductor and stabilizing agent. UV-VIS spectroscopy and Transmission Electron Microscopy (TEM) were used to characterize the amine AuNPs. Electrocatalytic activity of AuNPs allowed more sensitivity for a label-free detection of NS1 by square wave voltammetry (SWV), with linear response from 0.1 to 2 µg mL-1. It was found a good linearity (coefficient of correlation of 0.995 (p<0.01) and a limit of detection of 0.03 µg mL-1 NS1 for analytical responses. AuNP-NH2 synthesis provided an easy oriented immobilization of anti-NS1 antibodies by Fc portion, resulting in a simple fabrication immunosensor with relative high performance and feasibility for early diagnostic of DENV.


2013 ◽  
Vol 310 ◽  
pp. 177-182
Author(s):  
Song Bai Zhang ◽  
Bing Jun Zhang ◽  
Qian Liu ◽  
Xia Hu ◽  
Li Ying Zheng ◽  
...  

A label-free electrochemical biosensing strategy based on gold nanoparticle involved layer-by-layer self assembly for the detection of protein is proposed using platelet derived growth factor-BB dimer (PDGF-BB) as the model analyte. Utilizing the strong sulfur-Au affinity, ethanthiol and capture probe modified gold nanoparticles are self-assembled onto the surface of gold electrode successively. The aptamer probe for target protein hybridizes with the capture probe and the biosensor is fabricated. By measuring ac current voltammetry, the target protein can be sensitively detected in a linear dynamic range from 1-1000 ng/mL with a low detection limit of 0.5 ng/mL. Making use of self-assembled gold nanoparticles layer, a large amount of capture probes can be modified onto the gold electrode, supporting the high sensitivity of the proposed strategy. In addition, good reproducibility, high selectivity and stability are achieved. In particular, the biosensor can be easily regenerated by melting in hot water, making it reusable.


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