A microfluidic paper-based electrochemical biosensor array for multiplexed detection of metabolic biomarkers

Figures & data

Figure 1. A microfluidic paper-based electrochemical biosensor array that interfaces with a custom-made handheld potentiostat for multiplexed detection of metabolic biomarkers. (A) A paper-based electrochemical biosensor array (1 × 8). (B) A microcontroller-based multiplexing potentiostat mounted with a paper-based biosensor array. The potentiostat has eight measurement channels, and each channel is connected to a group of three sensing electrodes through metal clamps. CE: counter electrode. WE: working electrode. RE: reference electrode. (C) Schematic diagram of the potentiostat architecture with eight measurement channels. (D) A photograph of the paper-based biosensor array inserted into the potentiostat.

Figure 2. Electrochemical characterization of the paper-based biosensor array. (A) Typical cyclic voltammograms of 10 mM K₃[Fe(CN)₆] in 1 M KCl solution in an electrochemical biosensing module of the array device at various scan rates. (B) A plot of the cathodic peak current i_pc versus the square root of the scan rate ν^1/2, measured from the cyclic voltammograms (n = 5).

Figure 3. (A) Chronoamperometric curves and (B) the calibration plot for measurement of glucose in AU. The solid line in (B) represents a linear fit to experimental data with regression equation: y = 0.041x + 0.054 (R² = 0.996, n = 5).

Figure 4. (A) Chronoamperometric curves and (B) the calibration plot for measurement of lactate in AU. The solid line in (B) represents a linear fit to experimental data with regression equation: y = 0.0076x + 0.025 (R² = 0.995, n = 5).

Figure 5. (A) Chronoamperometric curves and (B) the calibration plot for measurement of uric acid in AU. The solid line represents a linear fit to experimental data with regression equation: y = 0.048x + 0.029 (R² = 0.994, n = 5).

Table 1. Performance comparison of the paper-based biosensor array with commercial meters [20] and μPAD in [14].

Analyte	Analytical performance (mM)
Dynamic linear range^a (this work)	Clinically relevant ranges [14]	LOD (this work)	LOD (commercial meters [20])	LOD [14]
Glucose	0–20	0.1–0.8	0.35	0.83	0.21
Lactate	0–25	5.5–22	1.76	1.1	0.36
Uric acid	0–10	1.5–4.4	0.52	N/A	1.38

a The dynamic linear ranges achieved in this work cover the clinically relevant ranges of the three biomarkers.

LOD: limit of detection.

NieZDeissFLiuX YAkbulutOWhitesidesG M 2010 Integration of paper-based microfluidic devices with commercial electrochemical readers Lab Chip 10 3163 3169 3163–9 10.1039/c0lc00237b

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