Amplified Analysis of Low-Molecular-Weight Substrates or Proteins by the Self-Assembly of DNAzyme−Aptamer Conjugates

Abstract

Blocked aptamer-DNAzyme conjugates act as aptasensors for the amplified analysis of adenosine 5‘-monophosphate or lysozyme.

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.…”

“…Optical detection has been the preferred means of transduction for the development of DNAzyme-based biosensors, usually with the use of ABTS, a reducing agent which becomes greenblue upon oxidation [4,[6][7][8][9]. On the other hand, electrochemical transduction has been chosen when DNA strands were immobilized onto electroactive surfaces [10][11][12].…”

Proximity hybridization-mediated isothermal exponential amplification for ultrasensitive electrochemical protein detection

“…In this way, Output can displace S2 from S1 successfully even it was partially complementary with S1. 44,45 After the S1-Output complex was released into the solution, in the presence of primer, the polymerase and nickase initiated EXPAR, during which Output was recycled and regenerated circularly. Meanwhile, S2 was free to hybridize with the capture-modified AuNPs.…”

Guanine Quadruplex Electrochemical Aptasensors

“…In comparison with protein peroxidases, the hemin/G4 peroxidase-mimicking DNAzymes have several advantages, such as high chemical stability, low cost and simple synthesis. Hemin/G4 DNAzyme electrochemical biosensors were successfully used for the detection of cells [106,107], proteins [108][109][110] or low molecular weight molecules, such as adenosine monophosphate (AMP) [102,111,112], anticancer drugs [113], gaseous ligands [114], toxins [115,116], pollutant agents [117,118] or metal ions [119,120].…”