Aptamer-modified nanomaterials: principles and applications

Porous silicon (PSi) thin films have been widely studied for biosensing applications, enabling label-free optical detection of numerous targets. The large surface area of these biosensors has been commonly recognized as one of the main advantages of the PSi nanostructure. However, in practice, without application of signal amplification strategies, PSi-based biosensors suffer from limited sensitivity, compared to planar counterparts. Using a theoretical model, which describes the complex mass transport phenomena and reaction kinetics in these porous nanomaterials, we reveal that the interrelated effect of bulk and hindered diffusion is the main limiting factor of PSi-based biosensors. Thus, without significantly accelerating the mass transport to and within the nanostructure, the target capture performance of these biosensors would be comparable, regardless of the nature of the capture probe–target pair. We use our model to investigate the effect of various structural and biosensor characteristics on the capture performance of such biosensors and suggest rules of thumb for their optimization.

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“…This has also high significance for maintaining active probes while immobilized, avoiding steric crowding effects. 82 , 84 …”

Section: Resultsmentioning

confidence: 99%

Mass Transfer Limitations of Porous Silicon-Based Biosensors for Protein Detection

et al. 2020

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“…FLGMs have been used to immobilize the thiolated DNA aptamer, providing a higher loading surface for the immobilization of aptamer on the electrode surface and also improved signal transduction by raising the electroactive surface area. 38,39 The sharp edges of the microstructures provides a highly reactive surface for chemically bonding to thiolated aptamer. 40 Activation process was conducted in 0.5 M H 2 SO 4 solution by CV from −0.1 to 1.3 V with scan rate of 0.1 V/s in order to obtain steady and repetitive voltammograms.…”

Section: Resultsmentioning

confidence: 99%

<p>An Electrochemical Aptasensor Platform Based on Flower-Like Gold Microstructure-Modified Screen-Printed Carbon Electrode for Detection of Serpin A12 as a Type 2 Diabetes Biomarker</p>

Maghsoudi¹,

Hassani²,

Akmal³

et al. 2020

IJN

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In the present study, a highly sensitive and simple electrochemical (EC) aptasensor for the detection of serpin A12 as a novel biomarker of diabetes was developed on a platform where flower-like gold microstructures (FLGMs) are electrodeposited onto a disposable screen-printed carbon electrode. Meanwhile, serpin A12-specific thiolated aptamer was covalently immobilized on the FLGMs. Methods: The electrochemical activity of a fabricated aptasensor under various conditions were examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Aptamer concentration, deposition time, self-assembly time, and incubation time were optimized for assay of serpin A12. The differential pulse voltammetry (DPV) was implemented for quantitative detection of serpin A12 in K 3 [Fe (CN) 6 ]/K 4 [Fe (CN) 6 ] solution (redox probe). Results: The label-free aptasensor revealed a linear range of serpin A12 concentration (0.039-10 ng/mL), detection limit of 0.020 ng/mL (S/N=3), and 0.031 ng/mL in solution buffer and plasma, respectively. Conclusion: The results indicate that this aptasensor has a high sensitivity, selectivity, stability, and acceptable reproducibility for detection of serpin A12 in diabetic patients.

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“…Nanomaterials can be incorporated in two manners: Nanoparticles as signalling elements and nanostructured surfaces as transducers or amplificators. For the former, aptasensors which incorporate gold nanoparticles (AuNPs) and quantum dots (QDs) were reported with promising sensitivity and signal amplification [ 46 , 47 ]. AuNP-based biosensors often operate with an optical transduction method since the aggregation of the nanoparticles upon aptamer-target binding leads to a wavelength shift from 520 nm to 650 nm.…”

Section: Aptasensorsmentioning

confidence: 99%

Aptasensors for Point-of-Care Detection of Small Molecules

et al. 2020

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Aptamers, a group of nucleic acids which can specifically bind to a target molecule, have drawn extensive interest over the past few decades. For analytics, aptamers represent a viable alternative to gold-standard antibodies due to their oligonucleic nature combined with advantageous properties, including higher stability in harsh environments and longer shelf-life. Indeed, over the last decade, aptamers have been used in numerous bioanalytical assays and in various point-of-care testing (POCT) platforms. The latter allows for rapid on-site testing and can be performed outside a laboratory by unskilled labor. Aptamer technology for POCT is not limited just to medical diagnostics; it can be used for a range of applications, including environmental monitoring and quality control. In this review, we critically examine the use of aptamers in POCT with an emphasis on their advantages and limitations. We also examine the recent success of aptasensor technology and how these findings pave the way for the analysis of small molecules in POCT and other health-related applications. Finally, the current major limitations of aptamers are discussed, and possible approaches for overcoming these challenges are presented.

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Aptamer-modified nanomaterials: principles and applications

Cited by 49 publications

References 127 publications

Mass Transfer Limitations of Porous Silicon-Based Biosensors for Protein Detection

Mass Transfer Limitations of Porous Silicon-Based Biosensors for Protein Detection

<p>An Electrochemical Aptasensor Platform Based on Flower-Like Gold Microstructure-Modified Screen-Printed Carbon Electrode for Detection of Serpin A12 as a Type 2 Diabetes Biomarker</p>

Aptasensors for Point-of-Care Detection of Small Molecules

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