scholarly journals Label-Free Impedimetric Immunosensors Modulated by Protein A/Bovine Serum Albumin Layer for Ultrasensitive Detection of Salbutamol

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 771
Author(s):  
Chia-Hung Lin ◽  
Ming-Jie Lin ◽  
Jie-De Huang ◽  
Yu-Sheng Chuang ◽  
Yu-Fen Kuo ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Electrochemical Impedance ◽  
Protein A ◽  
Great Promise ◽  
Igg Antibody ◽  
Simple Method ◽  
Sensing Properties ◽  
Relative Standard

The sensing properties of immunosensors are determined not only by the amount of immobilized antibodies but also by the number of effective antigen-binding sites of the immobilized antibody. Protein A (PA) exhibits a high degree of affinity with the Fc part of IgG antibody to feasibly produce oriented antibody immobilization. This work proposes a simple method to control the PA surface density on gold nanostructure (AuNS)-deposited screen-printed carbon electrodes (SPCEs) by mixing concentration-varied PA and bovine serum albumin (BSA), and to explore the effect of PA density on the affinity attachment of anti-salbutamol (SAL) antibodies by electrochemical impedance spectroscopy. A concentration of 100 μg/mL PA and 100 μg/mL BSA can obtain a saturated coverage on the 3-mercaptoproponic acid (MPA)/AuNS/SPCEs and exhibit a 50% PA density to adsorb the amount of anti-SAL, more than other concentration-varied PA/BSA-modified electrodes. Compared with the randomly immobilized anti-SAL/MPA/AuNS/SPCEs and the anti-SAL/PA(100 μg/mL):BSA(0 μg/mL)/MPA/AuNS/SPCE, the anti-SAL/PA(100 μg/mL): BSA(100 μg/mL)/MPA/AuNS/SPCE-based immunosensors have better sensing properties for SAL detection, with an extremely low detection limit of 0.2 fg/mL and high reproducibility (<2.5% relative standard deviation). The mixture of PA(100 μg/mL):BSA(100 μg/mL) for the modification of AuNS/SPCEs has great promise for forming an optimal protein layer for the oriented adsorption of IgG antibodies to construct ultrasensitive SAL immunosensors.

scholarly journals Comparison of Gold Nanoparticles Deposition Methods and Their Influence on Electrochemical and Adsorption Properties of Titanium Dioxide Nanotubes

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4269 ◽  
Author(s):  
Ewa Paradowska ◽  
Katarzyna Arkusz ◽  
Dorota G. Pijanowska
Keyword(s):  
Gold Nanoparticles ◽  
Titanium Dioxide ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Photoelectron Spectroscopy ◽  
Bovine Serum ◽  
Electrochemical Impedance ◽  
Electrochemical Characterizations ◽  
Titanium Dioxide Nanotubes ◽  
X Ray

The increasing interest of attachment of gold nanoparticles (AuNPs) on titanium dioxide nanotubes (TNTs) has been devoted to obtaining tremendous properties suitable for biosensor applications. Achieving precise control of the attachment and shape of AuNPs by methods described in the literature are far from satisfactory. This work shows the comparison of physical adsorption (PA), cyclic voltammetry (CV) and chronoamperometry (CA) methods and the parameters of these methods on TNTs properties. The structural, chemical, phase and electrochemical characterizations of TNTs, Au/TNTs, AuNPs/TNTs are carried out using scanning electron microscopy (SEM), electrochemical impedance spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy. The use of PA methods does not allow the deposition of AuNPs on TNTs. CV allows easily obtaining spherical nanoparticles, for which the diameter increases from 20.3 ± 2.9 nm to 182.3 ± 51.7 nm as a concentration of tetrachloroauric acid solution increase from 0.1 mM to 10 mM. Increasing the AuNPs deposition time in the CA method increases the amount of gold, but the AuNPs diameter does not change (35.0 ± 5 nm). Importantly, the CA method also causes the dissolution of the nanotubes layer from 1000 ± 10.0 nm to 823 ± 15.3 nm. Modification of titanium dioxide nanotubes with gold nanoparticles improved the electron transfer and increased the corrosion resistance, as well as promoted the protein adsorption. Importantly, after the deposition of bovine serum albumin, an almost 5.5-fold (324%) increase in real impedance, compared to TNTs (59%) was observed. We found that the Au nanoparticles—especially those with smaller diameter—promoted the stability of bovine serum albumin binding to the TNTs platform. It confirms that the modification of TNTs with gold nanoparticles allows the development of the best platform for biosensing applications.

Graphene Modified Molecular Imprinted Electrochemical Sensor for Specific Recognition of Bovine Serum Albumin

2013 ◽  
Vol 709 ◽  
pp. 891-894 ◽  
Author(s):  
Feng Li ◽  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Electrochemical Impedance ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Modified Glassy Carbon Electrode ◽  
Molecularly Imprinted ◽  
Active Probe ◽  
Pulse Voltammetry

A simple and efficient molecularly imprinted sensor (MIPs/GR/GCE) was firstly prepared by electropolymerization of pyrrole in the presence of bovine serum albumin (BSA) in an aqueous solution based on a graphene modified glassy carbon electrode for the selective recognition of bovine serum albumin. The prepared sensor was characterized by differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS), in which [Fe(CN)6]3−/4−was used as an electrochemical active probe. The results showed a wide linear range from 1.0 × 10-3to 1.0 × 10-9g/mL. And the imprinted biosensor indicated excellent selectivity and high sensitivity.

scholarly journals A simple method for non-denaturing purification of biotin-tagged proteins through competitive elution with free biotin

BioTechniques ◽  
2020 ◽  
Vol 68 (1) ◽  
pp. 41-44
Author(s):  
Kui Lin ◽  
Qin Yan ◽  
Audrey Mitchell ◽  
Natasha Funk ◽  
Catherlin Lu ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Protein Purification ◽  
Recovery Rate ◽  
Bovine Serum ◽  
Protein Denaturation ◽  
Simple Method ◽  
Agarose Beads ◽  
Elution Buffer ◽  
Neutral Conditions

The use of avidin or streptavidin in the purification of biotinylated proteins has been highly restricted due to the harsh and denaturing elution conditions. Here, we use biotinylated bovine serum albumin as a working model to demonstrate a simple and rapid method for biotin-tagged protein purification under non-denaturing conditions. The biotinylated bovine serum albumin is specifically bound to the anti-biotin antibody agarose beads and competitively eluted with free biotin under near-neutral conditions. The optimized elution conditions include using 4 mg/ml biotin (pH 8.5) as the elution buffer and allowing the buffer to incubate with agarose beads for 30 min prior to elution. The elution recovery rate is over 85% without apparent protein denaturation. The method is applicable for both immunoprecipitation and column chromatography.

Study on the interaction of bovine serum albumin with acid cyanine 5R and its application in analysis

2006 ◽  
Vol 84 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Fei Lu ◽  
Jing-Hao Pan ◽  
Yun Liu ◽  
Hongfen Zhang ◽  
Yujing Guo ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Binding Constant ◽  
Bovine Serum ◽  
Peak Potential ◽  
Buffer Solution ◽  
Solution Ph ◽  
Peak Current ◽  
Binding Ratio ◽  
Relative Standard

A supramolecular complex of bovine serum albumin (BSA) with acid cyanine 5R (AC 5R, C.I. acid blue 113, C.I.: 26360) has been shown to form in Tris–HCl buffer solution (pH 7.42) by linear sweep voltammetry (LSV), fluorimetry, and spectrophotometry. The binding ratio and binding constant of BSA with AC 5R have been detected by LSV and fluorimetry. The binding mechanism is also preliminarily discussed. In Tris–HCl buffer solution (pH 7.42), AC 5R can easily be reduced on the mercury electrode, and it has a well-defined LSV peak current (Ip) and peak potential (Ep) at –0.65 V (vs. SCE). In the presence of BSA, the Ipof AC 5R decreases, and the peak potential (Ep) shifts to a more positive potential. The decrease of the second-order derivative of reductive peak current (ΔIp") of AC 5R is proportional to the logarithm of BSA concentration in the range of 1.54 × 10–8mol·L–1– 1.54 × 10–5mol·L–1(r = 0.9931 – 0.9977). The limit of detection of BSA is 9.0 × 10–9mol·L–1. The relative standard deviation is 1.83% (n = 10), and the standard recovery is 97.5%–104.8%. This method can be used to determine BSA concentration on the basis of the interaction of BSA with AC 5R.Key words: bovine serum albumin (BSA), acid cyanine 5R (AC 5R), supramolecule, binding ratio, binding constant, fluorimetry, spectrophotometry, electroanalytical method.

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