Evaluation of quantum dots applied as switchable layer in a light-controlled electrochemical sensor.
Gold electrodes with switchable conductance are created by coating the gold surface with different colloidal quantum dots. For the quantum dot immobilization, a dithiol compound was used. By polarizing the electrode and applying a light pointer, local photocurrents were generated. The performance of this setup was characterized for a variety of different nanoparticle materials regarding drift and signal-to-noise ratio. We varied the following parameters: quantum dot materials and immobilization protocol. The results indicate that the performance of the sensor strongly depends on how the quantum dots are bound to the gold electrode. The best results were obtained by inclusion of an additional polyelectrolyte film, which had been fabricated using layer-by-layer assembly.
Yue
Zhao
Z
Department of Physics, Philipps University Marburg, 35037, Marburg, Germany.
Khalid
Waqas
W
Zanella
Marco
M
Abbasi
Azhar Zahoor
AZ
Pfreundt
Andrea
A
Rivera Gil
Pilar
P
Schubert
Kirsten
K
Lisdat
Fred
F
Parak
Wolfgang J
WJ
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D004867:Equipment Design; D006046:Gold / Q000737:chemistry; D045663:Quantum Dots
D006046:Gold