Direct electrochemistry and electrocatalysis of myoglobin based on silica-coated gold nanorods/room temperature ionic liquid/silica sol-gel composite film.
A novel biosensor based on the silica-coated gold nanorods (GNRs@SiO(2)) and hydrophilic room temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium tetrafluroborate ([bmim][BF(4)]) was fabricated for the determination of hydrogen peroxide (H(2)O(2)) and nitrite. GNRs@SiO(2) can not only act as a binder to hinder [bmim][BF(4)] (RTIL) leaking from the electrode surface, but also provide a favorable microenvironment for direct electrochemistry of myoglobin (Mb). A pair of well-defined and quasi-reversible redox peaks of Mb was obtained at the GNRs@SiO(2)-Mb/RTIL-sol-gel composite film modified GCE (GNRs@SiO(2)-Mb/RTIL-sol-gel/GCE) through direct electron transfer between Mb and the underlying electrode. This biosensor showed an excellent electrocatalytic activity towards hydrogen peroxide and nitrite. The linear range for the determination of H(2)O(2) was from 0.2 to 180 microM with a detection limit of 0.12 microM based on the signal-to-noise ratio of 3. In addition, the biosensor also exhibited high selectivity, good reproducibility, and long-term stability. Therefore, this kind of composite film can provide an ideal matrix for protein immobilization and biosensor fabrication.
Key Laboratory of Analytical Chemistry for Life Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
Wen-Lei
WL
Zhu
Yang
Y
Zhou
Jian-Rong
JR
Zhang
D015374:Biosensing Techniques; D002384:Catalysis; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D005782:Gels / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D009211:Myoglobin / Q000032:analysis* / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D019904:Polymethyl Methacrylate / Q000737:chemistry; D015203:Reproducibility of Results; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
C525963:1-butyl-3-methylimidazolium; D005782:Gels; D007093:Imidazoles; D052578:Ionic Liquids; D009211:Myoglobin; D006046:Gold; D012822:Silicon Dioxide; D019904:Polymethyl Methacrylate; D006861:Hydrogen Peroxide