scholarly journals Development of a Sensitive Electrochemical Enzymatic Reaction-Based Cholesterol Biosensor Using Nano-Sized Carbon Interdigitated Electrodes Decorated with Gold Nanoparticles

Sensors ◽  
2017 ◽  
Vol 17 (9) ◽  
pp. 2128 ◽  
Author(s):  
Deepti Sharma ◽  
Jongmin Lee ◽  
Junyoung Seo ◽  
Heungjoo Shin
Keyword(s):  
Gold Nanoparticles ◽  
Enzymatic Reaction ◽  
Interdigitated Electrodes ◽  
Cholesterol Biosensor

Bowl-like Nanoreactors Composed of Packed Gold Nanoparticles Surrounded with Silica Nanosheets for a Photothermally Enhancing Enzymatic Reaction

2020 ◽  
Vol 3 (11) ◽  
pp. 11465-11473
Author(s):  
Jiao Sun ◽  
Chen Cao ◽  
Jun Chen ◽  
Wenli Zhao ◽  
Qin Tang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Enzymatic Reaction

A cholesterol biosensor based on gold nanoparticles decorated functionalized graphene nanoplatelets

2011 ◽  
Vol 519 (16) ◽  
pp. 5667-5672 ◽  
Author(s):  
Sasidharan Sasikala Jyothirmayee Aravind ◽  
Tessy Theres Baby ◽  
Thevasahayam Arockiadoss ◽  
Raghavan Baby Rakhi ◽  
Sundara Ramaprabhu
Keyword(s):  
Gold Nanoparticles ◽  
Graphene Nanoplatelets ◽  
Functionalized Graphene ◽  
Cholesterol Biosensor

Gold Nanoparticle Enlargement Coupled with Fluorescence Decrease for Highly Sensitive Detection of Analytes

2011 ◽  
Vol 1301 ◽  
Author(s):  
Seong Yoon Lim ◽  
Jae Hong Kim ◽  
Joon Seok Lee ◽  
Chan Beum Park
Keyword(s):  
Gold Nanoparticles ◽  
Enzymatic Reaction ◽  
Optical Biosensor ◽  
Reducing Agents ◽  
Sensitive Detection ◽  
Detection Methods ◽  
Fluorescent Substrate ◽  
Reaction Solution ◽  
Highly Sensitive ◽  
Highly Sensitive Detection

ABSTRACTWe present a versatile and facile route for highly sensitive detection of analytes through coupling the enlargement of gold nanoparticles (Au NPs) with fluorescence decrease. The fluorescence intensity of dye molecules (e.g., fluorescein or rhodamine B) significantly decreased with the increasing concentration of reducing agents, such as hydrogen peroxide and hydroquinone. The sensitivity for the detection of reducing agents was much higher than other detection methods based on the absorbance measurement of enlarged gold nanoparticles or quantum dot-enzyme hybridization. We could successfully detect acetylthiocholine with the detection limit of several nM orders, using an enzymatic reaction by acetylcholinesterase, a key route for the detection of toxic organophosphate compounds. The fluorescence decreasing approach described in this work requires only a simple addition of fluorescence dye to the reaction solution without any chemical modification. The strategy of fluorescence decrease coupled with nanoparticle growth will be applied on the fluorescent substrate to develop detection templates for highly sensitive optical biosensor.

scholarly journals Detection of Sub-Nanomolar Concentration of Trypsin by Thickness-Shear Mode Acoustic Biosensor and Spectrophotometry

Biosensors ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 117
Author(s):  
Ivan Piovarci ◽  
Sopio Melikishvili ◽  
Marek Tatarko ◽  
Tibor Hianik ◽  
Michael Thompson
Keyword(s):  
Gold Nanoparticles ◽  
Protease Activity ◽  
Limit Of Detection ◽  
Colorimetric Assay ◽  
Enzymatic Reaction ◽  
Disease Diagnosis ◽  
Shear Mode ◽  
Label Free ◽  
Thickness Shear Mode ◽  
Thickness Shear

The determination of protease activity is very important for disease diagnosis, drug development, and quality and safety assurance for dairy products. Therefore, the development of low-cost and sensitive methods for assessing protease activity is crucial. We report two approaches for monitoring protease activity: in a volume and at surface, via colorimetric and acoustic wave-based biosensors operated in the thickness-shear mode (TSM), respectively. The TSM sensor was based on a β-casein substrate immobilized on a piezoelectric quartz crystal transducer. After an enzymatic reaction with trypsin, it cleaved the surface-bound β-casein, which increased the resonant frequency of the crystal. The limit of detection (LOD) was 0.48 ± 0.08 nM. A label-free colorimetric assay for trypsin detection has also been performed using β-casein and 6-mercaptohexanol (MCH) functionalized gold nanoparticles (AuNPs/MCH-β-casein). Due to the trypsin cleavage of β-casein, the gold nanoparticles lost shelter, and MCH increased the attractive force between the modified AuNPs. Consequently, AuNPs aggregated, and the red shift of the absorption spectra was observed. Spectrophotometric assay enabled an LOD of 0.42 ± 0.03 nM. The Michaelis–Menten constant, KM, for reverse enzyme reaction has also been estimated by both methods. This value for the colorimetric assay (0.56 ± 0.10 nM) is lower in comparison with those for the TSM sensor (0.92 ± 0.44 nM). This is likely due to the better access of the trypsin to the β-casein substrate at the surface of AuNPs in comparison with those at the TSM transducer.

A cascade amplification strategy based on rolling circle amplification and hydroxylamine amplified gold nanoparticles enables chemiluminescence detection of adenosine triphosphate

The Analyst ◽  
2014 ◽  
Vol 139 (15) ◽  
pp. 3796-3803 ◽  
Author(s):  
Ping Wang ◽  
Tonghuan Zhang ◽  
Taoyi Yang ◽  
Nan Jin ◽  
Yanjun Zhao ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Adenosine Triphosphate ◽  
Signal Amplification ◽  
Rolling Circle Amplification ◽  
Enzymatic Reaction ◽  
Chemiluminescence Detection ◽  
Rolling Circle ◽  
Amplification Strategy ◽  
Cascade Amplification

A chemiluminescent biosensor for ATP was developed by taking advantage of the ATP-dependent enzymatic reaction, the powerful signal amplification capability of rolling circle amplification, and hydroxylamine-amplified gold nanoparticles.

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