Label-free electrochemical aptasensor constructed by layer-by-layer technology for sensitive and selective detection of cancer cells

2015 ◽  
Vol 882 ◽  
pp. 32-37 ◽  
Author(s):  
Tianshu Wang ◽  
Jiyang Liu ◽  
Xiaoxiao Gu ◽  
Dan Li ◽  
Jin Wang ◽  
...  
2015 ◽  
Vol 7 (19) ◽  
pp. 8277-8284 ◽  
Author(s):  
Xue Liu ◽  
Hong-Lei Shuai ◽  
Ke-Jing Huang

In this work, an electrochemical aptasensor for the sensitive detection of platelet-derived growth factor BB (PDGF-BB) is fabricated based on leaf-like VS2 nanosheets which are prepared by a facile hydrothermal method.


RSC Advances ◽  
2014 ◽  
Vol 4 (94) ◽  
pp. 52250-52255 ◽  
Author(s):  
Jiawan Zhou ◽  
Wenyang Wang ◽  
Peng Yu ◽  
Erhu Xiong ◽  
Xiaohua Zhang ◽  
...  

A simple and label-free electrochemical biosensor based on a dopamine DNA aptamer was developed for the sensitive and selective detection of dopamine.


Chemosensors ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 52
Author(s):  
Qian Ma ◽  
Zhiqiang Gao ◽  
Hiranya Dayal ◽  
Sam Fong Yau Li

In this work, a simple and label-free fluorescence “off” to “on” platform was designed for the sensitive and selective detection of microRNA (miRNA) in cancer cells. This method utilized a padlock DNA-based rolling circle amplification (P-RCA) to synthesize fluorescent poly(thymine) (PolyT) which acted as a template for the synthesis of copper nanoparticles (CuNPs) within 10 minutes under mild conditions. While the repeated PolyT sequence was used as the template for CuNP synthesis, other non-PolyT parts (single strand-DNAs without the capacity to act as the template for CuNP formation) served as “smart glues” or rigid linkers to build complex nanostructures. Under the excitation wavelength of 340 nm, the synthesized CuNPs emitted strong red fluorescence effectively at 620 nm. To demonstrate the use of this method as a universal biosensor platform, lethal-7a (let-7a) miRNA was chosen as the standard target. This sensor could achieve highly sensitive and selective detection of miRNA in the presence of other homologous analogues for the combination of P-RCA with the fluorescent copper nanoparticle. Overall, this novel label-free method holds great potential in the sensitive detection of miRNA with high specificity in real samples.


2018 ◽  
Vol 10 (48) ◽  
pp. 41089-41097 ◽  
Author(s):  
Veronika Urbanová ◽  
Kolleboyina Jayaramulu ◽  
Andreas Schneemann ◽  
Štěpán Kment ◽  
Roland A. Fischer ◽  
...  

2021 ◽  
Vol 379 ◽  
pp. 138172
Author(s):  
Maham Liaqat ◽  
Sara Riaz ◽  
Mian Hasnain Nawaz ◽  
Mihaela Badea ◽  
Akhtar Hayat ◽  
...  

Cancers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 123
Author(s):  
Monika Kujdowicz ◽  
Wojciech Placha ◽  
Brygida Mech ◽  
Karolina Chrabaszcz ◽  
Krzysztof Okoń ◽  
...  

Markers of bladder cancer cells remain elusive, which is a major cause of the low recognition of this malignant neoplasm and its recurrence. This implies an urgent need for additional diagnostic tools which are based on the identification of the chemism of bladder cancer. In this study, we employed label-free techniques of molecular imaging—Fourier Transform Infrared and Raman spectroscopic imaging—to investigate bladder cancer cell lines of various invasiveness (T24a, T24p, HT-1376, and J82). The urothelial HCV-29 cell line was the healthy control. Specific biomolecules discriminated spatial distribution of the nucleus and cytoplasm and indicated the presence of lipid bodies and graininess in some cell lines. The most prominent discriminators are the total content of lipids and sugar moieties as well as the presence of glycogen and other carbohydrates, un/saturated lipids, cytochromes, and a level of S-S bridges in proteins. The combination of the obtained hyperspectral database and chemometric methods showed a clear differentiation of each cell line at the level of the nuclei and cytoplasm and pointed out spectral signals which differentiated bladder cancer cells. Registered spectral markers correlated with biochemical composition changes can be associated with pathogenesis and potentially used for the diagnosis of bladder cancer and response to experimental therapies.


Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 180
Author(s):  
Lucia Sarcina ◽  
Giuseppe Felice Mangiatordi ◽  
Fabrizio Torricelli ◽  
Paolo Bollella ◽  
Zahra Gounani ◽  
...  

The early detection of the human immunodeficiency virus (HIV) is of paramount importance to achieve efficient therapeutic treatment and limit the disease spreading. In this perspective, the assessment of biosensing assay for the HIV-1 p24 capsid protein plays a pivotal role in the timely and selective detection of HIV infections. In this study, multi-parameter-SPR has been used to develop a reliable and label-free detection method for HIV-1 p24 protein. Remarkably, both physical and chemical immobilization of mouse monoclonal antibodies against HIV-1 p24 on the SPR gold detecting surface have been characterized for the first time. The two immobilization techniques returned a capturing antibody surface coverage as high as (7.5 ± 0.3) × 1011 molecule/cm2 and (2.4 ± 0.6) × 1011 molecule/cm2, respectively. However, the covalent binding of the capturing antibodies through a mixed self-assembled monolayer (SAM) of alkanethiols led to a doubling of the p24 binding signal. Moreover, from the modeling of the dose-response curve, an equilibrium dissociation constant KD of 5.30 × 10−9 M was computed for the assay performed on the SAM modified surface compared to a much larger KD of 7.46 × 10−5 M extracted for the physisorbed antibodies. The chemically modified system was also characterized in terms of sensitivity and selectivity, reaching a limit of detection of (4.1 ± 0.5) nM and an unprecedented selectivity ratio of 0.02.


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