Yagati, Ajay Kumar and Behrent, Arne and Beck, Sebastian and Rink, Simone and Goepferich, Achim M. and Min, Junhong and Lee, Min-Ho and Baeumner, Antje J. (2020) Laser-induced graphene interdigitated electrodes for label-free or nanolabel-enhanced highly sensitive capacitive aptamer-based biosensors. BIOSENSORS & BIOELECTRONICS, 164: 112272. ISSN 0956-5663, 1873-4235
Full text not available from this repository. (Request a copy)Abstract
Highly porous laser-induced graphene (LIG) is easily generated in complex electrode configurations such as interdigitated electrodes (IDEs). Here, we demonstrate that their superior capacitive response at low frequencies can be exploited in affinity biosensors using thrombin aptamers as model biorecognition elements. Of specific interest was the effect of electrode surface area on capacitance detection, and the comparison between a labelfree format and enhancement strategies afforded by carboxy group bearing polymeric nanoparticles or liposomes. Electrochemical impedance spectroscopy (EIS) was used to investigate the LIG performance and optimize the biosensor design. Interestingly, the label-free strategy performed extremely well and additional labels decreased the limit of detection or increased the sensitivity only minimally. It is assumed that the highly porous nature of the LIG structures dominates the capacitive response so that labels removed from the surface have only limited influence Also, while slight performance changes can be observed for smaller vs. larger electrode structures, the performance of a LIG IDE is reasonably independent of its size. In the end, a dynamic range of 5 orders of magnitude was obtained (0.01 nM-1000 nM) with a limit of detection as low as 0.12 pM. When measured in serum, this increased to 1.3 pM. The good reproducibility (relative standard deviation (RSD), 4.90%) and repeatability (RSD, 2.59%) and good long-term stability (>7 weeks at 4 degrees C) prove that a LIG-based capacitance sensor is an excellent choice for affinity-based biosensor. The ease-of-production, the simplicity of modification and the superior performance even in a label-free format indicate that LIG-based biosensors should be considered in point-of-care diagnostics in the future.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | ELECTROCHEMICAL APTASENSOR; HEMIN/G-QUADRUPLEX; THROMBIN; GENERATION; NANOTUBES; ASSAYS; DNA; Aptamer; Liposomes; Interdigitated electrodes; Nanoparticles; Impedance; Capacitance; Laser-induced graphene |
| Subjects: | 500 Science > 540 Chemistry & allied sciences 600 Technology > 615 Pharmacy |
| Divisions: | Chemistry and Pharmacy > Institute of Pharmacy Chemistry and Pharmacy > Institute of Pharmacy > Pharmaceutical Technology (Prof. Göpferich) Chemistry and Pharmacy > Institut für Analytische Chemie, Chemo- und Biosensorik Chemistry and Pharmacy > Institut für Analytische Chemie, Chemo- und Biosensorik > Chemo- und Biosensorik (Prof. Antje J. Bäumner, formerly Prof. Wolfbeis) |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 11 Mar 2021 12:38 |
| Last Modified: | 11 Mar 2021 12:38 |
| URI: | https://pred.uni-regensburg.de/id/eprint/43799 |
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