White blood cell counting on smartphone paper electrochemical sensor.
White blood cell (WBC) analysis provides rich information in rapid diagnosis of acute bacterial and viral infections as well as chronic disease management. For patients with immune deficiency or leukemia WBC should be persistently monitored. Current WBC counting method relies on bulky instrument and trained personnel and is time consuming. Rapid, low-cost and portable solution is in highly demand for point of care test. Here we demonstrate a label-free smartphone based electrochemical WBC counting device on microporous paper with patterned gold microelectrodes. WBC separated from whole blood was trapped by the paper with microelectrodes. WBC trapped on the paper leads to the ion diffusion blockage on microelectrodes, therefore cell concentration is determined by peak current on the microelectrodes measured by a differential pulse voltammeter and the quantitative results are collected by a smartphone wirelessly within 1min. We are able to rapidly quantify WBC concentrations covering the common physiological and pathological range (200-20000μL-1) with only 10μL sample and high repeatability as low as 10% in CoV (Coefficient of Variation). The unique smartphone paper electrochemical sensor ensures fast cell quantification to achieve rapid and low-cost WBC analysis at the point-of-care under resource limited conditions.
Micro and Nanotechnology Lab, University of Illinois at Urbana-Champaign, Urbana 61801, USA; Department of Electrical Engineering, University of Illinois at Urbana-Champaign, Urbana 61801, USA.
Xinhao
X
Wang
Department of Immunology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; Micro and Nanotechnology Lab, University of Illinois at Urbana-Champaign, Urbana 61801, USA. Electronic address: ghlin@illinois.edu.
Guohong
G
Lin
Department of Electrical Engineering, University of Illinois at Urbana-Champaign, Urbana 61801, USA.
Guangzhe
G
Cui
Micro and Nanotechnology Lab, University of Illinois at Urbana-Champaign, Urbana 61801, USA; Department of Electrical Engineering, University of Illinois at Urbana-Champaign, Urbana 61801, USA.
Xiangfei
X
Zhou
Micro and Nanotechnology Lab, University of Illinois at Urbana-Champaign, Urbana 61801, USA; Department of Electrical Engineering, University of Illinois at Urbana-Champaign, Urbana 61801, USA; School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China. Electronic address: loganliu@illinois.edu.
Gang Logan
GL
Liu
D015374:Biosensing Techniques; D006801:Humans; D007958:Leukocyte Count / Q000379:methods*; D007962:Leukocytes / Q000473:pathology*; D010209:Paper; D000068997:Smartphone
Diffusion impedance; Label-free; Paper electrochemical; Point-of-care; Smartphone; White blood cell