Covalent Coupling of Organophosphorus Hydrolase Loaded Quantum Dots to Carbon Nanotube/Au Nanocomposite for Enhanced Detection of Methyl Parathion
An amperometric biosensor for highly selective and sensitive determination of methyl parathion (MP) was developed based on dual signal amplification: (1) a large amount of introduced enzyme on the electrode surface and (2) synergistic effects of nanoparticles towards enzymatic catalysis. The fabrication process includes (1) electrochemical deposition of gold nanoparticles by a multi-potential step technique at multiwalled carbon nanotube (MWCNT) film pre-cast on a glassy carbon electrode and (2) immobilization of methyl parathion degrading enzyme (MPDE) onto a modified electrode through CdTe quantum dots (CdTe QDs) covalent attachment. The introduced MWCNT and gold nanoparticles significantly increased the surface area and exhibited synergistic effects towards enzymatic catalysis. CdTe QDs are further used as carriers to load a large amount of enzyme. As a result of these two important enhancement factors, the proposed biosensor exhibited extremely sensitive, perfectly selective, and rapid response to methyl parathion in the absence of a mediator.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 973700
- Report Number(s):
- PNNL-SA-69507; TRN: US201006%%1069
- Journal Information:
- Biosensors and Bioelectronics, 25(6):1370-1375, Vol. 25, Issue 6
- Country of Publication:
- United States
- Language:
- English
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