US 11,946,098 B2
Calibration-free measurement with electrochemical biosensors
Kevin Plaxco, Santa Barbara, CA (US); Hui Li, Wuhan (CN); Philip Dauphin-Ducharme, Santa Barbara, CA (US); and Gabriel Ortega, Santa Barbara, CA (US)
Assigned to The Regents of the University of California, Oakland, CA (US)
Appl. No. 16/618,352
Filed by The Regents of the University of California, Oakland, CA (US)
PCT Filed Jun. 1, 2018, PCT No. PCT/US2018/035648
§ 371(c)(1), (2) Date Nov. 30, 2019,
PCT Pub. No. WO2018/223024, PCT Pub. Date Dec. 6, 2018.
Claims priority of provisional application 62/513,796, filed on Jun. 1, 2017.
Prior Publication US 2020/0182820 A1, Jun. 11, 2020
Int. Cl. G01N 27/327 (2006.01); A61B 5/00 (2006.01); C12Q 1/6825 (2018.01)
CPC C12Q 1/6825 (2013.01) [A61B 5/6867 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method of measuring a concentration of a target species in a sample by a process:
presenting the sample to an electrochemical sensor of a selected design, under a selected set of assay conditions; wherein the electrochemical sensor comprises a plurality of recognition elements bound to an electrode substrate; wherein each recognition element reversibly binds the target species; wherein one or more redox reporter species is associated with each recognition element; and wherein an output of the sensor, upon application of a suitable potential pulse, is a current comprising electron flow between the redox reporter species and the electrode substrate;
wherein a ratio of target-saturated output signal to target-free output signal is known for sensors of the selected design operated under the selected assay conditions;
wherein a ratio of signal output at a minimally-responsive frequency to target-free output signal is known for sensors of the selected design operated under the selected assay conditions;
performing a first interrogation comprising the application of a series of potential pulses to the sensor at a responsive pulse frequency to obtain an output value i, wherein the responsive frequency is a frequency which results in a sensor output that is dependent upon the concentration of the target species in the sample;
performing a second interrogation of the sample comprising the application of a series of potential pulses to the sensor at a minimally responsive pulse frequency to obtain an output value iNR; and
calculating the concentration of the target species by use of: i; iNR; the ratio of target-saturated output signal to target-free output signal; and the ratio of signal output at the minimally-responsive frequency to target-free output signal.