A novel and versatile sensing platform based on HRP-mimicking DNAzyme-catalyzed template-guided deposition of polyaniline.
A novel, simple, and versatile amperometric sensing platform was developed based on HRP-mimicking DNAzyme-catalyzed template-guided deposition of polyaniline (PANI). Pb(2+) was chosen as a model to demonstrate the proof-of-concept of our approach. The Pb(2+) aptamer was first self-assembled on the electrode surface. Upon addition of Pb(2+), Pb(2+) bound to its aptamer to form G-quadruplex (G4). HRP-mimicking DNAzyme with peroxidase catalytic activity was successfully generated after hemin was efficiently intercalated into the G4 structure. Subsequently, HRP-mimicking DNAzyme catalyzed oxidation of aniline to PANI with H(2)O(2) exclusively at the G4 structures, which lead to a readily measurable "turn-on" electrochemical signal. The constructed platform exhibited a good linear response toward Pb(2+) over a wide range of concentration from 1.0×10(-9) M to 1.0×10(-6) M with the detection limit of 5.0×10(-10) M. The high performance DNAzyme-based strategy can be further extended to quantify a wide variety of analytes.
College of Chemistry, Chemical Engineering and Materials Science, Engineering Research Center of Pesticide and Medicine Intermediate Clean Production, Ministry of Education, Key Laboratory of Molecular and Nano Probes, Shandong Normal University, Jinan 250014, People's Republic of China.
Feng
F
Li
Limin
L
Yang
Mingqin
M
Chen
Yi
Y
Qian
Bo
B
Tang
D000814:Aniline Compounds / Q000737:chemistry*; D040761:Biomimetic Materials / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D021881:DNA, Catalytic / Q000737:chemistry*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006735:Horseradish Peroxidase / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis*; D054802:Molecular Imprinting / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000814:Aniline Compounds; D021881:DNA, Catalytic; C416807:polyaniline; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase