A Capacitance-to-Frequency Converter with On-Chip Passivated Microelectrodes for Bacteria Detection in Saline Buffers up to 575 MHz
(2015) IEEE Transactions on Circuits and Systems. Part 2: Express Briefs — Vol. 62, n° 2, p. 159-163 (2015)
Files
manuscript_IEEE.pdf
Closed Access - Adobe PDF
- 1.59 MB
ACapacitance-to-FrequencyConverterWithOn-ChipPassivatedMicroelectrodesforBacteriaDetectioninSalineBuffersUpto575MHz.pdf
Restricted Access - Adobe PDF
- 624.95 KB
Details
- Authors
- Abstract
- To enable impedimetric sensing of whole-cell bacteria in saline buffer with passivated microelectrodes, we designed a very high frequency (up to 575 MHz) CMOS oscillator connected to on-chip Al/Al2O3 interdigitated microelectrodes. The output frequency was theoretically and experimentally shown to be inversely proportional to the permittivity of the solution with maximal error of 2 %, up to an electrical conductivity of 1 S/m. As a biosensing proof-of-concept, successful experimental detection of whole-cell Staphylococcus epidermidis was performed in physiological buffers, showing a detection limit of 10^7 CFU/ml after 20 min of bacterial incubation. The 0.25 μm CMOS circuit, combining sensing/readout parts, has a 0.05 mm2 area, consumes 29 mW at 250 kS/s and can be connected to microcontrollers, making the system suitable for point-of-care diagnostics.
- Affiliations
Citations
Couniot, N., Bol, D., Poncelet, O., Francis, L., & Flandre, D. (2015). A Capacitance-to-Frequency Converter with On-Chip Passivated Microelectrodes for Bacteria Detection in Saline Buffers up to 575 MHz. IEEE Transactions on Circuits and Systems. Part 2: Express Briefs, 62(2), 159-163. https://doi.org/10.1109/TCSII.2014.2369111 (Original work published 2015)