Table 1.
Feature comparison of literature reviewed potentiostats with the proposed device.
Fig 1.
Graphical representation of the covalent immobilization of anti-S100B onto AUIDEs using a cysteamine/EDC approach.
Fig 2.
General representation of the system components.
Fig 3.
Potentiostat circuit with TIA circuit.
Analog switches (MAX4641 and ADG704) are controlled by Teensy LC (not shown) and isolate the electrochemical cell. The TIA gain is controlled by one of four resistors selected by the ADG704 switch.
Fig 4.
Components of TBISTAT connected for EIS measurement on an AUIDE cell.
LiPo battery and boost circuit (bottom left) powers the MCU through two cables (red 5 V, black ground). The BM is connected to the MCU (top left) using four-pin male-female headers. The MCU is connected to the PC through ten cables (two for 3.3 V and ground (red and black), two for I2C communication (SDA purple, SCL white), one for ADC (yellow), and five for Analog switches and TIA resistance multiplexer (blue)). A card reader (top right) is connected to the electrochemical cell female header connector (bottom right of PC). The smartphone is shown running the TBISTAT application.
Table 2.
Current draw of TBISTAT for standby and operation modes.
Fig 5.
Current noise of TBISTAT for the 10–10000 Hz bandwidth and 10 KΩ-1MΩ TIA gain resistors.
Fig 6.
EIS magnitude and phase plots for TBISTAT and reference instrument for dummy cell excitation.
Fig 7.
EIS magnitude and phase plots for TBISTAT and reference instrument for measurements in 10mM K3[Fe(CN)6] in 0.2M KCl solution.
Fig 8.
EIS magnitude and phase plots for TBISTAT and reference instrument in ANTI-S100B functionalized thin-film AUIDEs exposed to 316 pg/ml of S100B spiked human plasma samples.
Fig 9.
Nyquist plot comparisons of TBISTAT and reference instrument in detecting S100B in an ANTI-S100B functionalized thin-film AUIDEs exposed to 316 pg/ml of S100B spiked human plasma sample.
Table 3.
Statistical analysis of single-frequency analysis experiment.
Fig 10.
Nyquist plots of AUIDEs experimental results in spiked human plasma samples for the quantification of S100B in the 31–316 pg/mL range.
Fig 11.
Calibration curve for S100B in spiked human plasma using AUIDEs.
y = ΔRCT; x = [S100B] (pg/mL).
Fig 12.
Brain injury support information after the EIS test.