scholarly journals Confined gold nanoparticles enhance the detection of small molecules in label-free impedance aptasensors

Nanoscale ◽  
2015 ◽  
Vol 7 (17) ◽  
pp. 7763-7769 ◽  
Author(s):  
Ana S. Peinetti ◽  
Helena Ceretti ◽  
Martín Mizrahi ◽  
Graciela A. González ◽  
Silvana A. Ramírez ◽  
...  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rozita Abolhasan ◽  
Balal Khalilzadeh ◽  
Hadi Yousefi ◽  
Sahar Samemaleki ◽  
Forough Chakari-Khiavi ◽  
...  

AbstractIn the present article, we developed a highly sensitive label-free electrochemical immunosensor based on NiFe-layered double hydroxides (LDH)/reduced graphene oxide (rGO)/gold nanoparticles modified glassy carbon electrode for the determination of receptor tyrosine kinase-like orphan receptor (ROR)-1. In this electrochemical immunoassay platform, NiFe-LDH/rGO was used due to great electron mobility, high specific surface area and flexible structures, while Au nanoparticles were prepared and coated on the modified electrodes to improve the detection sensitivity and ROR1 antibody immobilizing (ROR1Ab). The modification procedure was approved by using cyclic voltammetry and differential pulse voltammetry based on the response of peak current to the step by step modifications. Under optimum conditions, the experimental results showed that the immunosensor revealed a sensitive response to ROR1 in the range of 0.01–1 pg mL−1, and with a lower limit of quantification of 10 attogram/mL (10 ag mL−1). Furthermore, the designed immunosensor was applied for the analysis of ROR1 in several serum samples of chronic lymphocytic leukemia suffering patients with acceptable results, and it also exhibited good selectivity, reproducibility and stability.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Ehsan Shokri ◽  
Morteza Hosseini ◽  
Mehdi D. Davari ◽  
Mohammad R. Ganjali ◽  
Maikel P. Peppelenbosch ◽  
...  

2017 ◽  
Vol 98 ◽  
pp. 134-139 ◽  
Author(s):  
Dong-Mei Wang ◽  
Qi-Qi Gai ◽  
Rong-Fu Huang ◽  
Xingwang Zheng

2018 ◽  
Vol 185 ◽  
pp. 10006 ◽  
Author(s):  
Natalia V. Guteneva ◽  
Sergey L. Znoyko ◽  
Alexey V. Orlov ◽  
Maxim P. Nikitin ◽  
Petr I. Nikitin

Precise quantitative and highly sensitive detection of small molecules (haptens) is highly demanded in medicine, food quality control, in vitro diagnostics, criminalistics, environmental monitoring, etc. In the present work, the magnetic method of particle quantification and the optical methods of spectral correlation and spectral phase interferometry complement each other for optimization of a quantitative assay for measuring concentrations of small molecules. The assay employs magnetic nanoparticles as labels in rapid immunochromatographic format. The approach was demonstrated with fluorescein as a model molecule. The interferometric label-free biosensors were employed for selection of optimal reagents that produced high specificity and sensitivity. The method of magnetic particle quantification counted the magnetic labels over the entire volume of the immunochromatographic membrane to provide their distribution along the test strip. Such distribution was used for optimization of such parameters as concentrations of the used reagents and of antibody immobilized on the labels, amount of the labels and conjugates of haptens with protein carriers to realize the advanced quantitative immunochromatographic assay.


RSC Advances ◽  
2015 ◽  
Vol 5 (70) ◽  
pp. 56583-56589 ◽  
Author(s):  
Yulan Wang ◽  
Dan Wu ◽  
Yong Zhang ◽  
Xiang Ren ◽  
Yaoguang Wang ◽  
...  

In this work, a novel and ultrasensitive label-free electrochemical immunosensor was developed for the quantitative detection of alpha fetoprotein (AFP).


2020 ◽  
Author(s):  
Rhushabh Maugi ◽  
bernadette gamble ◽  
david bunka ◽  
Mark Platt

A universal aptamer-based sensing strategy is proposed using DNA modified nanocarriers and Resistive Pulse Sensing for the rapid and label free detection of small molecules. The surface of a magnetic nanocarrier was first modified with a ssDNA aka linker which is designed to be partially complimentary in sequence to a ssDNA aptamer. The aptamer and linker form a stable dsDNA complex on the nanocarriers surface. Upon the addition of the target molecule, a conformational change takes place where the aptamer preferentially binds to the target over the linker; causing the aptamer to be released into solution. The RPS measures the change in velocity of the nanocarrier as its surface changes from dsDNA to ssDNA, and its velocity is used as a proxy for the concentration of the target. We illustrate the versatility of the assay by demonstrating the detection of the antibiotic Moxifloxacin, and chemotherapeutics Imatinib and Irinotecan.


2016 ◽  
Vol 27 (2) ◽  
pp. 643-649 ◽  
Author(s):  
Xiao-Yu Wang ◽  
Cheng-Gang Niu ◽  
Li-Juan Guo ◽  
Liu-Yin Hu ◽  
Sheng-Quan Wu ◽  
...  

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