(163c) Reusable Electrochemical Cyclodextrin Biosensor for Resveratrol Detection
AIChE Annual Meeting
Monday, November 11, 2019 - 1:06pm to 1:24pm
The technique presented will involve modifying a gold electrode surface with polyethylene glycol (PEG)-SH via thiol chemistry. The surface PEG brushes were then complexed with Î±âCD. The CD-PEG surface was exposed to different concentrations of resveratrol. We monitored the change in double layer capacitance, which is proportional to the release of CD from the PEG surface. Compared to the bare surface, sensitivity was improved. To check the reusability of the surface, after each serial dilution, the surface was reloaded with CD, and a new serial dilution was performed. It was found that CD was successfully reloaded on the PEG brushes. Attenuated total reflectance â Fourier transform infrared and X-ray photoelectron spectroscopy tests were also carried out to verify impedance results both for initial surface modification and CD reloading. As a control, we did resveratrol serial dilution with a bare surface and a modified PEG surface in which double layer capacitance stayed constant. Moreover, a time control experiment with a CD-PEG surface was carried out. In this experiment we put our modified surface in a PBS solution and measured capacitance every 5 minutes; no changes in double layer capacitance was observed in this experiment either. Finally, the capacitive response of our CD-PEG surface to cortisol was investigated. As it was predicted the Î±âCD surface only showed some selectivity towards cortisol. Therefore, we have created a semi-selective reusable sensor towards the detection of molecules that interact with Î±âCD, such as resveratrol in the range 500 pM to 20 nM.