Lab in a tube: a fast-assembled colorimetric sensor for highly sensitive detection of oligonucleotides based on a hybridization chain reaction

摘要: In this work, a one-pot signal amplified strategy was constructed based on generating hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme as the color product for detection of DNA sequences. A sequence associated with hepatitis B virus (HBV) selected model target. The enzyme-free and label-free biosensor contained three oligonucleotide terms target DNA, hairpin structures H1 H2 which were partially complementary. It should be noted that G-quadruplex structure hidden in H2. absence THBV, hairpins stable enough due to complementary sequences at end oligodeoxynucleotides, made it difficult complete self-assembly. Upon addition self-assembly THBV allows rest facilitate H1–H2 complex formation releases next cycle. presence hemin K+, liberated form structure, could catalyze achromatous tetramethylbenzidine (TMB) into colored product. change solution quantitated by spectrophotometry naked eye. We also employed 20% ethanol buffer accelerate strand displacement reaction (DSDR), cut down time process from 12 h 1 h. limit colorimetric sensor is 9.5 pM, linear range 50 pM 100 nM.