A new biosensor detection system to overcome the Debye screening effect: dialysis-silicon nanowire field effect transistor

Figures & data

Figure 1 The relationship between debye length and ionic strength.

Figure 2 (A) The detection principle of SiNW-FET. (B) The principle of the Debye screening effect. (C–E) A schematic diagram of a miniature blood dialyzer.

Abbreviation: SiNW-FET, silicon nanowire field effect transistor.

Figure 3 The fabrication process for silicon nanowire devices.

Abbreviation: SiNW, silicon nanowire.

Figure 4 The process of functional modification of silicon nanowires.

Figure 5 The image of the miniature blood dialyzer.

Figure 6 The structure and properties of silicon nanowire devices. (A) An SEM image of SiNW. (B) A schematic of the distribution of the electrodes in a silicon nanowire device. (C) The transfer curve image. (D) The output curve image.

Abbreviation: SiNW, silicon nanowire.

Figure 7 The results of functional silicon nanowire modification. (A) The AFM image of functioned SiNW. (B) The results after modification of the fluorescent protein. Abbreviation: SiNW, silicon nanowire.

Table 1 Compositional variation in the serum before and after dialysis

	Before dialysis	After dialysis
K^+	4.11 mmol/L	0.150 mmol/L
Na^+	139.4 mmol/L	3.762 mmol/L
Cl^−	106.9 mmol/L	0.0043 mmol/L
Ca^2+	2.29 mmol/L	0.0834 mmol/L
Creatinine	57.2 µmol/L	Less than detection limit (4.1 µmol/L)
Urea	3.1 mmol/L	Less than detection limit (0.1 mmol/L)
Uric ucid	231.7 µmol/L	Less than detection limit (2.4 µmol/L)
Serum albumin	44.9 g/L	43.6 g/L
PH	7.4	7.4
The volume of serum	30 ml	30 ml
AFP	2.49 ng/ml	2.49 ng/ml
CEA	2.46 ng/ml	2.46 ng/ml

Figure 8 The detection results on Dialysis–SiNW-FET. (A) The standard solution detection results of anti-CEA SiNW-FET. (B) The standard solution detection results of anti-AFP SiNW-FET. (C) The standard solution detection results of no antibody SiNW-FET and anti-BSA SiNW-FET. (D) The serum detection results of anti-CEA SiNW-FET. (E) The serum detection results of anti-AFP SiNW-FET. (F) The serum detection results of anti-BSA SiNW-FET.

Abbreviation: SiNW-FET, silicon nanowire field effect transistor.

Figure 9 The human serum detection results of different tumor markers. (A) The human serum detection results with different CEA concentrations. (B) The human serum detection results with different AFP concentrations.