A Novel Approach to Monitor the Concentration of Phosphate Buffers in the Range of 1 M to 0.1 M Using a Silicon-Based Impedance Sensor
Abstract
:1. Introduction
2. Materials and Methods
2.1. Sodium Phosphate Buffer Preparation and Characterization
2.2. Silicon-Based Impedance Sensor
2.3. Impedance Spectroscopy
2.4. Impedance Modeling
3. Results and Discussion
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
Appendix A
Appendix B
26 μL | Top Contact | p+n Junction | Bottom Contact | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
CAu/liq (μF) | RAu/liq (kΩ) | Cj (nF) | Rj (kΩ) | Rliq (kΩ) | CAu/Si(p+) (nF) | RAu/Si(p+) (kΩ) | Cp+n (nF) | Rp+n (kΩ) | Rs (Ω) | CSi(n)/Au (nF) | RSi(n)/Au (Ω) | |
Aliquot 1 | ||||||||||||
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 25.70 | 7.00 | 17.00 | 14.00 |
1.00 M | 0.31 | 15.00 | 400.00 | 2.20 | 1.80 | 20.00 | 12.00 | 8.00 | 27.30 | 8.00 | 17.00 | 26.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 25.70 | 7.00 | 17.00 | 14.00 |
0.75 M | 0.65 | 28.00 | 130.00 | 10.50 | 1.80 | 20.00 | 14.00 | 9.00 | 24.80 | 8.00 | 15.00 | 29.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 28.00 | 7.00 | 17.00 | 14.00 |
0.50 M | 0.70 | 5.20 | 110.00 | 7.50 | 2.00 | 20.00 | 17.00 | 6.70 | 27.80 | 8.00 | 16.00 | 29.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 8.00 | 5.80 | 23.40 | 6.00 | 16.00 | 15.00 |
0.25 M | 1.50 | 4.70 | 250.00 | 6.00 | 1.00 | 20.00 | 21.00 | 8.70 | 25.40 | 8.00 | 10.00 | 53.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 25.70 | 7.00 | 17.00 | 14.00 |
0.10 M | 0.70 | 15.00 | 25.00 | 2.80 | 0.60 | 20.00 | 25.00 | 12.00 | 25.80 | 9.00 | 8.00 | 55.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 15.55 | 7.00 | 17.00 | 14.00 |
0.05 M | 0.50 | 9.50 | 53.00 | 8.80 | 0.70 | 20.00 | 26.00 | 10.20 | 16.90 | 7.00 | 11.00 | 80.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 18.00 | 7.00 | 17.00 | 14.00 |
0.01 M | 0.80 | 35.0 | 47.00 | 11.80 | 1.20 | 20.00 | 26.00 | 12.00 | 19.00 | 7.00 | 11.00 | 80.00 |
26 μL | Top Contact | p+n Junction | Bottom Contact | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
CAu/liq (μF) | RAu/liq (kΩ) | Cj (nF) | Rj (kΩ) | Rliq (kΩ) | CAu/Si(p+) (nF) | RAu/Si(p+) (kΩ) | Cp+n (nF) | Rp+n (kΩ) | Rs (Ω) | CSi(n)/Au (nF) | RSi(n)/Au (Ω) | |
Aliquot 2 | ||||||||||||
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 25.60 | 7.00 | 17.00 | 14.00 |
1.00 M | 0.40 | 22.00 | 130.00 | 10.20 | 1.80 | 20.00 | 12.00 | 8.00 | 24.60 | 8.00 | 21.00 | 28.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 25.60 | 7.00 | 17.00 | 14.00 |
0.75 M | 0.62 | 10.00 | 500.00 | 3.50 | 2.10 | 20.00 | 14.00 | 9.20 | 27.10 | 9.00 | 15.00 | 23.00 |
Empty | 20.00 | 0.30 | 170.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 25.60 | 7.00 | 17.00 | 14.00 |
0.50 M | 0.90 | 6.20 | 150.00 | 6.50 | 2.50 | 20.00 | 17.00 | 8.20 | 26.30 | 8.00 | 16.00 | 29.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.30 | 16.00 | 8.00 | 5.90 | 22.90 | 6.00 | 16.00 | 15.00 |
0.25 M | 1.50 | 9.00 | 220.00 | 6.50 | 1.20 | 20.00 | 21.00 | 9.50 | 24.20 | 8.00 | 10.00 | 33.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 25.70 | 7.00 | 17.00 | 14.00 |
0.10 M | 1.00 | 18.00 | 23.00 | 2.80 | 0.30 | 20.00 | 25.00 | 12.00 | 26.90 | 9.00 | 10.00 | 35.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 15.55 | 7.00 | 17.00 | 14.00 |
0.05 M | 0.60 | 11.50 | 59.00 | 5.20 | 1.00 | 20.00 | 25.00 | 12.10 | 16.00 | 7.00 | 8.00 | 50.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 18.00 | 7.00 | 17.00 | 14.00 |
0.01 M | 1.75 | 15.00 | 47.00 | 11.50 | 0.90 | 20.00 | 26.00 | 12.50 | 18.60 | 7.00 | 13.00 | 52.00 |
26 μL | Top Contact | p+n Junction | Bottom Contact | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
CAu/liq (μF) | RAu/liq (kΩ) | Cj (nF) | Rj (kΩ) | Rliq (kΩ) | CAu/Si(p+) (nF) | RAu/Si(p+) (kΩ) | Cp+n (nF) | Rp+n (kΩ) | Rs (Ω) | CSi(n)/Au (nF) | RSi(n)/Au (Ω) | |
Aliquot 3 | ||||||||||||
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 24.40 | 7.00 | 17.00 | 14.00 |
1.00 M | 0.52 | 21.00 | 500.00 | 6.50 | 2.60 | 20.00 | 12.00 | 10.60 | 24.80 | 9.00 | 17.00 | 18.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 24.40 | 7.00 | 17.00 | 14.00 |
0.75 M | 0.63 | 14.00 | 460.00 | 3.90 | 2.40 | 20.00 | 14.00 | 10.30 | 25.20 | 8.00 | 15.00 | 33.00 |
Empty | 20.00 | 0.30 | 170.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 25.40 | 7.00 | 17.00 | 14.00 |
0.50 M | 1.15 | 4.50 | 400.00 | 4.80 | 2.50 | 20.00 | 17.00 | 9.60 | 26.30 | 8.00 | 16.00 | 48.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.30 | 16.00 | 8.00 | 5.90 | 22.70 | 6.00 | 16.00 | 15.00 |
0.25 M | 1.40 | 6.50 | 500.00 | 5.00 | 1.40 | 20.00 | 21.00 | 10.50 | 23.60 | 8.00 | 12.00 | 34.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 25.70 | 7.00 | 17.00 | 14.00 |
0.10 M | 1.70 | 7.50 | 26.00 | 2.80 | 0.30 | 20.00 | 25.00 | 12.30 | 26.60 | 9.00 | 10.00 | 50.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 15.55 | 7.00 | 17.00 | 14.00 |
0.05 M | 0.70 | 12.00 | 59.00 | 5.20 | 0.80 | 20.00 | 25.00 | 11.80 | 17.00 | 7.00 | 8.00 | 80.00 |
Empty | 20.00 | 0.30 | 160.00 | 2.80 | 2.25 | 16.00 | 11.00 | 5.90 | 18.00 | 7.00 | 17.00 | 14.00 |
0.01 M | 1.80 | 10.00 | 47.00 | 11.80 | 0.80 | 20.00 | 26.00 | 12.00 | 20.10 | 7.00 | 12.00 | 40.00 |
Appendix C
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1 M NaH2PO4 (mL) | 1 M Na2HPO4 (mL) | pH (Experiment) |
---|---|---|
80 | 20 | 5.50 (Aliquot 1) |
50 | 50 | 6.38 (Aliquot 2) |
20 | 80 | 7.12 (Aliquot 3) |
Aliquot | Concentration of Aliquot (M) | pH (Experiment) DI Water pH 7.45 | pH (Experiment) DI Water pH 5.56 |
---|---|---|---|
Aliquot 1 | 1.00 | 5.50 | 5.67 |
0.75 | 5.65 | 5.76 | |
0.50 | 5.84 | 5.91 | |
0.25 | 6.00 | 6.10 | |
0.10 | 6.27 | 6.30 | |
0.05 | 6.30 | 6.40 | |
0.01 | 6.65 | 6.55 | |
Aliquot 2 | 1.00 | 6.38 | 6.42 |
0.75 | 6.41 | 6.53 | |
0.50 | 6.46 | 6.61 | |
0.25 | 6.63 | 6.71 | |
0.10 | 6.70 | 6.89 | |
0.05 | 6.93 | 6.96 | |
0.01 | 6.97 | 7.15 | |
Aliquot 3 | 1.00 | 7.12 | 7.18 |
0.75 | 7.13 | 7.31 | |
0.50 | 7.15 | 7.32 | |
0.25 | 7.25 | 7.40 | |
0.10 | 7.35 | 7.52 | |
0.05 | 7.40 | 7.59 | |
0.01 | 7.38 | 7.75 |
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Bhat, V.J.; Blaschke, D.; Müller, E.; Ehricht, R.; Schmidt, H. A Novel Approach to Monitor the Concentration of Phosphate Buffers in the Range of 1 M to 0.1 M Using a Silicon-Based Impedance Sensor. Biosensors 2023, 13, 841. https://doi.org/10.3390/bios13090841
Bhat VJ, Blaschke D, Müller E, Ehricht R, Schmidt H. A Novel Approach to Monitor the Concentration of Phosphate Buffers in the Range of 1 M to 0.1 M Using a Silicon-Based Impedance Sensor. Biosensors. 2023; 13(9):841. https://doi.org/10.3390/bios13090841
Chicago/Turabian StyleBhat, Vinayak J., Daniel Blaschke, Elke Müller, Ralf Ehricht, and Heidemarie Schmidt. 2023. "A Novel Approach to Monitor the Concentration of Phosphate Buffers in the Range of 1 M to 0.1 M Using a Silicon-Based Impedance Sensor" Biosensors 13, no. 9: 841. https://doi.org/10.3390/bios13090841
APA StyleBhat, V. J., Blaschke, D., Müller, E., Ehricht, R., & Schmidt, H. (2023). A Novel Approach to Monitor the Concentration of Phosphate Buffers in the Range of 1 M to 0.1 M Using a Silicon-Based Impedance Sensor. Biosensors, 13(9), 841. https://doi.org/10.3390/bios13090841