Surface‐Plasmonic‐Field‐Induced Photoredox Catalysis and Mediated Electron Transfer for Washing‐Free DNA Detection

Abstract

Distance-dependent electromagnetic radiation and electron transfer have been commonly employed in washingfree fluorescence and electrochemical bioassays,r espectively. In this study,w ec ombined the two distance-dependent phenomena for sensitive washing-free DNAd etection. A distance-dependent surface plasmonic field induces rapid photoredox catalysis of surface-bound catalytic labels,a nd distance-dependent mediated electron transfer allows for rapid electron transfer from the surface-bound labels to the electrode. An optimal system consists of achemically reversible acceptor (Ru(NH 3) 6 3+), ac hemically reversible photoredoxc atalyst (eosin Y), and ac hemically irreversible donor (triethanolamine). Side reactions with O 2 do not significantly decrease the efficiency of photoredox catalysis.E nergy transfer quenching between the electrode and the label can be lowered by increasing the distance between them. Washing-free DNA detection had ad etection limit of approximately 0.3 nm in buffer and 0.4 nm in serum without aw ashing step.

FRET Imaging of Nonuniformly Distributed DNA SAMs on Gold Reveals the Role Played by the Donor/Acceptor Ratio and the Local Environment in Measuring the Rate of Hybridization

“…The detection of biomolecules using functionalized surfaces has been realized using optical and/or electrochemical methods. − Sensors using nucleic acids as the surface-bound probes have been successful in the detection of a variety of analytes, from DNA and small molecules to proteins. ,,, One common approach is to prepare a DNA self-assembled monolayer (SAM) via a thiol bond to the gold. The tethered DNA probe can be single stranded DNA (ssDNA), an aptamer, or a DNA hairpin.…”

DNA Hairpins and Dumbbell-Wheel Transitions Amplified Walking Nanomachine for Ultrasensitive Nucleic Acid Detection

“…SARS-CoV-2 RNA testing of respiratory samples is an important way to prevent and control the coronavirus disease 2019 (COVID-19) pandemic . Accurate determination of the concentrations of target DNA or RNA plays a critical role in the diagnosis and prognosis of certain diseases, which should be intensively investigated. , Based on the definite Watson–Crick base pairing principle, nucleic acid analysis can be achieved by converting hybridization information into detectable signals like commonly used fluorescence. , Currently, standard techniques for the quantification of nucleic acid include classical polymerase chain reaction (PCR), digital PCR (dPCR), microarray, next-generation sequencing (NGS), mass spectrometry, and so on. However, the requirements of complicated equipment, expensive reagents, and tedious reaction steps restrict their wide applications in clinical scenes.…”

“…5 Accurate determination of the concentrations of target DNA or RNA plays a critical role in the diagnosis and prognosis of certain diseases, which should be intensively investigated. 6,7 Based on the definite Watson−Crick base pairing principle, nucleic acid analysis can be achieved by converting hybridization information into detectable signals like commonly used fluorescence. 8,9 Currently, standard techniques for the quantification of nucleic acid include classical polymerase chain reaction (PCR), digital PCR (dPCR), 10 microarray, 11 next-generation sequencing (NGS), 12 mass spectrometry, 13 and so on.…”

Sensitive Affinity-Based Biosensor Using the Autocatalytic Activation of Trypsinogen Mutant by Trypsin with Low Self-activation

“…Electrochemical affinity-based biosensors have been widely developed for simple, sensitive point-of-care testing. ,, Highly amplified electrochemical signals are produced in electrochemical biosensors when the rapid generation of a signaling species by a catalytic label is combined with the rapid redox cycling of the signaling species. ,− Many catalytic protease reactions are also compatible with redox cycling because the additional (bio)­chemical species used for redox cycling do not influence proteolytic reaction rates. ,− Proteolytic catalytic reactions, especially those of trypsin, can be performed in the presence of additional species involved in redox cycling. , …”