Reversible switches of DNA nanostructures between “Closed” and “Open” states and their biosensing applications

Abstract

A novel and versatile biosensing platform based on the structural conversion of 3D DNA nanostructures from ETDNA (Equilateral Triangle) to TPFDNA (Triangular Pyramid Frustum) was proposed for the first time. The inputs of aptamers and their relative targets made the DNA structure change from the "Open" to the "Closed" state, leading to the faradaic impedance changes as the output signals. The specific properties of excellent stability and specific rigid structure of 3D DNA nanostructures made the biosensor function as a regenerable, reusable and intelligent platform. The sensor exhibited excellent selectivity for IFN-γ detection with a wide linear range of 1.0 × 10(-9) to 2.0 × 10(-6) M and a low detection limit of 5.2 × 10(-10) M. The distinctive features of DNA nanostructures make them potentially advantageous for a broad range of biosensing, bionanoelectronics, and therapeutic applications.

Simple and Efficient Method to Purify DNA–Protein Conjugates and Its Sensing Applications

“…DNA molecules have been widely used in analytical chemistry as an excellent class of recognition moiety for selective detection of many target substances . The targets include not only complementary DNA or RNA through nucleic acid hybridization, but also metal ions, organic molecules, proteins and even cells, through functional DNAs that are capable of either catalyzing reactions (DNAzymes), − binding target molecules (DNA aptamers), − or both (DNA aptazymes). − Functional DNAs are obtained via a combinatorial technique known as in vitro selection or systematic evolution of ligands by exponential enrichment (SELEX), ,, and have been found to recognize a variety of analytes with high specificity and affinity. − By using DNAs labeled with suitable signal reporters as sensors, a series of analytical techniques, such as fluorescence, ,− colorimetry, − electrochemistry, ,− flow cytometry, − magnetic resonance, , and surface enhanced Raman scattering − have been successfully applied for the detection with high sensitivity and selectivity.…”

Advanced biosensors for monitoring astronauts’ health during long-duration space missions

“…The device reusability can be obtained by employing microparticles as a solid phase, which are then replenished with fresh ones for the subsequent analysis, although this approach does not fully accomplish the concept of zero-waste. Future development can be envisaged with the use of molecular switches as biospecific recognition elements, that exploit reversible binding with the target analyte (Xiong et al, 2017;Sheng et al, 2013). However, device reusability still poses critical aspects that must be carefully considered.…”

Graphene-Assisted Label-Free Homogeneous Electrochemical Biosensing Strategy based on Aptamer-Switched Bidirectional DNA Polymerization

“…Among different electrochemical transducer techniques, electrochemical impedance biosensor is a very powerful analytical tool for label-free analysis of interfacial properties related to biorecognition events occurring at the modified electrode interfaces, in addition to being nondestructive and highly sensitive. − Therefore, in this contribution, taking the discrimination ability of graphene over ssDNA/dsDNA in combination with the electrochemical impedance biosensor, we developed a novel label-free homogeneous DNA-based electrochemical biosensor with ultrahigh sensitivity to overcome the aforementioned problem without immobilization of any bioprobe. Recently, graphene has been widely studied as a promising type of electrode material in the fields of electrochemical biosensing, − because of its large surface area and high electrical conductivity.…”