Electrochemical DNA Biosensors Based on Labeling with Nanoparticles

Abstract

This work reviews the field of DNA biosensors based on electrochemical determination of nanoparticle labels. These labeling platforms contain the attachment of metal nanoparticles (NPs) or quantum dots (QDs) on the target DNA or on a biorecognition reporting probe. Following the development of DNA bioassay, the nanotags are oxidized to ions, which are determined by voltammetric methods, such as pulse voltammetry (PV) and stripping voltammetry (SV). The synergistic effects of NPs amplification (as each nanoprobe releases a large number of detectable ions) and the inherent sensitivity of voltammetric techniques (e.g., thanks to the preconcentration step of SV) leads to the construction of ultrasensitive, low cost, miniaturized, and integrated biodevices. This review focuses on accomplishments in DNA sensing using voltammetric determination of nanotags (such as gold and silver NPs, and Cd- and Pb-based QDs), includes published works on integrated three electrode biodevices and paper-based biosystems, and discusses strategies for multiplex DNA assays and signal enhancement procedures. Besides, this review mentions the electroactive NP synthesis procedures and their conjugation protocols with biomolecules that enable their function as labels in DNA electrochemical biosensors.

Applications of Graphene Quantum Dots in Biomedical Sensors

“…This makes them suitable for the development of biosensors [30][31][32][33]. Additionally, they are often used for signal amplification by serving as nanocarriers including electron transfer promoters, nanozymes, detector bioreceptors, electroactive labeling elements, and catalysts [34][35][36][37], hence offering novel strategies for biosensing platforms and their practical applicability. Over the last decade, numerous nanomaterials have been continuously studied and employed as signal-amplifying species such as nanoparticles (NPs) [38][39][40], graphene [41][42][43], nanowires [44], carbon nanotubes (CNTs) [45], magnetic beads [46,47] and quantum dots (QDs) [48,49].…”

Nano- and biosensors for the detection of SARS-CoV-2: challenges and opportunities

“…24 To solve the problem, nanomaterials can be employed as labels to obtain the remarkable improvement of signal, high enough to be easily detectable. 50,55,56 As an example, metallic nanomaterials (e.g., gold or silver NPs) and quantum dots can be analyzed and employed for labeling by attaching on the targeted DNA/bio-recognizing probe. 55,56 This can make a synergetic effect due to the nano-labeling consequences to significantly amplify the electrochemical signal, and make it possible to design ultrasensitive and selective labeledbiosensing strategies.…”

“…50,55,56 As an example, metallic nanomaterials (e.g., gold or silver NPs) and quantum dots can be analyzed and employed for labeling by attaching on the targeted DNA/bio-recognizing probe. 55,56 This can make a synergetic effect due to the nano-labeling consequences to significantly amplify the electrochemical signal, and make it possible to design ultrasensitive and selective labeledbiosensing strategies. 56 In this regard, future studies should be performed based on taking the advantages of various attractive physicochemical characteristics of nanoscaled materials (especially optical, electrical, magnetic, and opto-magnetic properties) for development of nanoenabled biosensing approaches to specific detection of viruses, especially MERS-CoV, SARS-CoV and SARS-CoV-2 (Table 3).…”

Nanobioconjugates for Signal Amplification in Electrochemical Biosensing

“…NPs or NSs of conducting materials, metals or QDs can be used in connection to a proper electrochemical technique for enhancing the signal response of a biorecognition event. For instance, there are many reports in the literature where the target analyte is followed by metallic NP- or NS-based nanobioconjugate dissolution, which signal response is registered by anodic (or cathodic) stripping voltammetry or anodic (or cathodic) redissolution voltammetry [ 36 , 37 ]. Figure 2 shows representative examples of electrochemical biosensors developed with noble nanomaterial-based nanobioconjugates and Table 1 summarizes the analytical features of the biosensors described.…”