N-Methyl-4-hydrazino-7-nitrobenzofurazan: a fluorogenic substrate for peroxidase-like DNAzyme, and its potential application

Abstract

Characterization and optimization studies of N-methyl-4-hydrazino-7-nitrobenzofurazan (MNBDH) as a new fluorogenic substrate in the peroxidation reaction catalyzed by DNAzyme are reported. The effects of pH, H2O2 concentration, metal-cation type, and the concentration and type of surfactant on the fluorescence intensity were investigated. The optimized reaction was subsequently used for the development of an assay for DNA detection based on a molecular-beacon probe. The use of a fluorogenic substrate enabled the detection of a single-stranded DNA target with a 1 nmol L−1 detection limit.Graphical Abstractᅟ

Optical and electrochemical detection of a verotoxigenic E. coli gene using DNAzyme-labeled stem-loops

“…Based on strategies similar to those reported previously [4][5][6][7][8][9][10][11]17], the aim of the present work was to prove the hypothesis that, by employing small-volume electrochemical cells in combination with inexpensive untreated printed electrodes, a sensitive detection of specific sequences of verotoxigenic E. coli could be carried out using DNAzymes as soluble electrochemical labels, yielding similar results to those obtained with the more usual optical detection. To that end, the conditions for the optimum response of a peroxidase DNAzyme were firstly optimized (pH, buffer composition, potassium ion concentration and hemin-to-oligonucleotides ratio) for electrochemical response.…”

Allosterically regulated DNA-based switches: From design to bioanalytical applications

“…At this stage, the formed G-quadruplex in the presence of hemin can exhibit its peroxidase-like activity and an optical signal output is measured. Such strategy has been adapted to create sensors based on electrochemical [71], label-free electrochemiluminescent [72] and fluorescence detection [73,74].…”

Utilization of G‐Quadruplex‐Forming Aptamers for the Construction of Luminescence Sensing Platforms

“…A DNAzyme‐based approach that uses the oxidizing ability of the hemin–G‐quadruplex assembly is another way to transfer the DNA switching event into the luminescence signal. Once formed, the hemin–G‐quadruplex assembly could oxidize a non‐emissive precursor compound into an emissive fluorophore …”