Aptamers, biosensor

Several electrical aptamer biosensors implemented the biocatalytic hydrolytic activities of thrombin, or the fact that proteins (e.g., thrombin) often include several binding sites for the formation of supramolecular complexes with different aptamers. The bioelectrocatalytic detection of thrombin by an electrical aptasensor was demonstrated by formation of an aptamer-thrombin complex on the electrode, followed by a thrombin-mediated hydrolysis of the nitroaniline-functionalized peptide, (22), yielding the redox-active product nitroaniline, (23), which was analyzed electrochemically76 (Fig. 12.20b). A further bioelectrocatalytic aptasensors configuration is depicted in Fig. 12.20c, where the multidentate formation of aptamer-protein supramolecular complexes was used to analyze thrombin.76 Thrombin includes two different binding sites for aptamers.77 One of the thrombin aptamers... 

For preparation of aptamer biosensor use gold electrode of 2-mm diameter (CH Instruments Inc., USA). The electrode should be carefully cleaned as follows first immerse it in chloroform (Merck) and extensively clean in an ultrasound bath sonicator for 3 min. Use ultrasound... 

Keywords Aptamer Biosensor Electrochemistry Nanoparticle Nanoscale... 

Aptamer biosensor Drolet, Moon-Dermott, and Roming20... 

Tombelli, S. and Mascini, M. (2010) Aptamers biosensors for pharmaceutical compounds. Combinatorial Chemistry High Throughput Screening, 13 (7), 641-549. 

Rodriguez, M. C., Kawde, A-N., Wang, J. (2005). Aptamer biosensor for label-free impedance spectroscopy detection of proteins based on recognition-induced switching of the surface charge. Chem Commun 34, 4267-4269. 

A novel signal-on junction-probe-based ECL aptamer biosensor for the detection of thrombin was constructed. Figure 6.6 shows experimental principle of the junction-probe ECL aptamer biosensor for the detection of thrombin. Compared with some other ECL aptamer sensors, the proposed ECL aptamer biosensor has the advantages of higher sensitivity, lower background current, better selectivity and reusability, fabrication easiness, and operation convenience. These features make it a promising alternative to conventional thrombin detection methods and this method is expected to be involved in biochip fabrication [25]. 

Fig. 6.6 Experimental principle of the junction-probe ECL aptamer biosensor for the detection of thrombin. Reprinted with permission from Ref. [25]. Copyright 2010 Elsevier BV...

Zhang J, Chen P, Wu X, Chen J, Xu L, Chen G, Fu F (2011) A signal-on electrochemiluminescence aptamer biosensor for the detection of ultratrace thrombin based on junction-probe. Biosens Bioelectron 26(5) 2645-2650. doi 10.1016/j.bios.2010.11.028... 

Wang Z, Duan N, Hun X, Wu S (2010) Electrochemiluminescent aptamer biosensor for the determination of ochratoxin A at a gold-nanoparticles-modified gold electrode using N-(aminobutyl)-N-ethylisoluminol as a luminescent label. Anal Bioanal Chem 398(5) 2125-2132. doi 10.1007/s00216-010 146-l... 

Strehlitz, B. Nikolaus, N. Stoltenburg, R. Protein detection with aptamer biosensors. 

Sun C, et al. A label-free and high sensitive aptamer biosensor based on hyperbranched polyester microspheres for thrombin detection. Anal ChimActa 2014 850 33-40. 

Hu, R., Wen, W., Wang, Q., Xiong, H., Zhang, X., Gu, H., Wang, S., 2014. Novel electrochemical aptamer biosensor based on an enzyme-gold nanoparticle dual label for the ultrasensitive detection of epithelial tumour marker MUC1. Biosens. Bioelectron. 53, 384—389. 

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