Electrochemical detection of DNA hybridization by using a zirconia modified renewable carbon paste electrode.
A simple, polishable and renewable DNA biosensor was fabricated based on a zirconia modified carbon paste electrode. Zirconia was mixed with graphite powder and paraffin wax to produce the paste for the electrode, and response-optimized at 56% graphite powder, 19% ZrO(2) and 25% paraffin wax. An oligonucleotide probe with a terminal 5'-phosphate group was attached to the surface of the electrode via the strong affinity of zirconia for phosphate groups. DNA immobilization and hybridization were characterized by cyclic voltammetry and differential pulse voltammetry, using methylene blue as indicator. Examination of changes in response with complementary or non-complementary DNA sequences showed that the developed biosensor had a high selectivity and sensitivity towards hybridization detection (< or =2x10(-10) M complementary DNA detectable). The surface of the biosensor can be renewed quickly and reproducibly (signal RSD+/-4.6% for five successive renewals) by a simple polishing step.
Zuo
Shao-Hua
SH
Research Center of Analysis & Test and Institute of Advanced Materials, East China University of Science and Technology, Shanghai 200237, PR China.
Zhang
Ling-Fan
LF
Yuan
Hui-Hui
HH
Lan
Min-Bo
MB
Lawrance
Geoffrey A
GA
Wei
Gang
G
D015374:Biosensing Techniques / Q000379:methods; D002244:Carbon; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D017743:Equipment Reuse; D009693:Nucleic Acid Hybridization / Q000379:methods*; D015345:Oligonucleotide Probes; D015040:Zirconium
D015345:Oligonucleotide Probes; D002244:Carbon; D015040:Zirconium; C028541:zirconium oxide