TY - JOUR
T1 - Ultrasensitive electrochemical detection of miRNA-21 by using an iridium(III) complex as catalyst
AU - Miao, Xiangmin
AU - Wang, Wanhe
AU - Kang, Tianshu
AU - Liu, Jinbiao
AU - Shiu, Kwok Keung
AU - Leung, Chung Hang
AU - Ma, Edmond Dik Lung
N1 - Funding Information:
This work is supported by Hong Kong Baptist University ( FRG2/14-15/004 and FRG2/15-16/002 ), the Health and Medical Research Fund ( HMRF/14130522 ), the Research Grants Council ( HKBU/201811 , HKBU/204612 , and HKBU/201913 ), the French Agence Nationale de la Recherche/Research Grants Council Joint Research Scheme (AHKBU201/12; Oligoswitch ANR-12-IS07-0001), the National Natural Science Foundation of China ( 21575121 ), the Guangdong Province Natural Science Foundation ( 2015A030313816 ), the Hong Kong Baptist University Century Club Sponsorship Scheme 2015, the Interdisciplinary Research Matching Scheme ( RC-IRMS/14-15/06 ), the Science and Technology Development Fund , Macao SAR ( 098/2014/A2 ), and the University of Macau ( MYRG091(Y3-L2)-ICMS12-LCH , MYRG2015-00137-ICMS-QRCM , and MRG044/LCH/2015/ICMS ).
PY - 2016/12/15
Y1 - 2016/12/15
N2 - The ultrasensitive electrochemical detection of miRNA-21 was realized by using a novel redox and catalytic “all-in-one” mechanism with an iridium(III) complex as a catalyst. To construct such a sensor, a capture probe (CP) was firstly immobilized onto the gold electrode surface. In the presence of miRNA-21, a sandwiched DNA complex could form between CP and a methylene blue (MB) labeled G-rich detection probe modified onto a gold nanoparticle (AuNP) surface (DP-AuNPs). Upon addition of K+, the structure of DP changed to a G-quadruplex. Then, the iridium(III) complex could selectively interact with the G-quadruplex, catalyzing the reduction of H2O2, which was accompanied by an electrochemical signal change using MB as an electron mediator. Under optimal conditions, the electrochemical signal of MB reduction peak was proportional to miRNA concentration in the range from 5.0 fM to 1.0 pM, with a detection limit of 1.6 fM. In addition, satisfactory results were obtained for miRNA-21 detection in human serum samples, indicating a potential application of the sensor for bioanalysis.
AB - The ultrasensitive electrochemical detection of miRNA-21 was realized by using a novel redox and catalytic “all-in-one” mechanism with an iridium(III) complex as a catalyst. To construct such a sensor, a capture probe (CP) was firstly immobilized onto the gold electrode surface. In the presence of miRNA-21, a sandwiched DNA complex could form between CP and a methylene blue (MB) labeled G-rich detection probe modified onto a gold nanoparticle (AuNP) surface (DP-AuNPs). Upon addition of K+, the structure of DP changed to a G-quadruplex. Then, the iridium(III) complex could selectively interact with the G-quadruplex, catalyzing the reduction of H2O2, which was accompanied by an electrochemical signal change using MB as an electron mediator. Under optimal conditions, the electrochemical signal of MB reduction peak was proportional to miRNA concentration in the range from 5.0 fM to 1.0 pM, with a detection limit of 1.6 fM. In addition, satisfactory results were obtained for miRNA-21 detection in human serum samples, indicating a potential application of the sensor for bioanalysis.
KW - Electrochemical biosensor
KW - Iridium(III) complex
KW - miRNA-21
UR - http://www.scopus.com/inward/record.url?scp=84978916765&partnerID=8YFLogxK
U2 - 10.1016/j.bios.2016.07.001
DO - 10.1016/j.bios.2016.07.001
M3 - Journal article
C2 - 27424263
AN - SCOPUS:84978916765
SN - 0956-5663
VL - 86
SP - 454
EP - 458
JO - Biosensors and Bioelectronics
JF - Biosensors and Bioelectronics
ER -