| 1. |
- Shafaat, Atefeh, et al.
(författare)
-
Glucose-to-Resistor Transduction Integrated into a Radio-Frequency Antenna for Chip-less and Battery-less Wireless Sensing
- 2022
-
Ingår i: ACS Sensors. - : American Chemical Society (ACS). - 2379-3694. ; 7:4, s. 1222-1234
-
Tidskriftsartikel (refereegranskat)abstract
- To maximize the potential of 5G infrastructure in healthcare, simple integration of biosensors with wireless tag antennas would be beneficial. This work introduces novel glucose-to-resistor transduction, which enables simple, wireless biosensor design. The biosensor was realized on a near-field communication tag antenna, where a sensing bioanode generated electrical current and electroreduced a nonconducting antenna material into an excellent conductor. For this, a part of the antenna was replaced by a Ag nanoparticle layer oxidized to high-resistance AgCl. The bioanode was based on Au nanoparticle-wired glucose dehydrogenase (GDH). The exposure of the cathode-bioanode to glucose solution resulted in GDH-catalyzed oxidation of glucose at the bioanode with a concomitant reduction of AgCl to highly conducting Ag on the cathode. The AgCl-to-Ag conversion strongly affected the impedance of the antenna circuit, allowing wireless detection of glucose. Mimicking the final application, the proposed wireless biosensor was ultimately evaluated through the measurement of glucose in whole blood, showing good agreement with the values obtained with a commercially available glucometer. This work, for the first time, demonstrates that making a part of the antenna from the AgCl layer allows achieving simple, chip-less, and battery-less wireless sensing of enzyme-catalyzed reduction reaction.
|
|
| 2. |
- Thirabowonkitphithan, Pannawich, et al.
(författare)
-
Electrogenicity of microbial biofilms of medically relevant microorganisms : potentiometric, amperometric and wireless detection.
- 2024
-
Ingår i: Biosensors & bioelectronics. - : Elsevier. - 0956-5663 .- 1873-4235. ; 246
-
Tidskriftsartikel (refereegranskat)abstract
- Since the progression of biofilm formation is related to the success of infection treatment, detecting microbial biofilms is of great interest. Biofilms of Gram-positive Staphylococcus aureus and Streptococcus gordonii bacteria, Gram-negative Pseudomonas aeruginosa and Escherichia coli bacteria, and Candida albicans yeast were examined using potentiometric, amperometric, and wireless readout modes in this study. As a biofilm formed, the open circuit potential (OCP) of biofilm hosting electrode (bioanode) became increasingly negative. Depending on the microorganism, the OCP ranged from −70 to −250 mV. The co-culture generated the most negative OCP (−300 mV vs Ag/AgCl), while the single-species biofilm formed by E. coli developed the least negative (−70 mV). The OCP of a fungal biofilm formed by C. albicans was −100 mV. The difference in electrode currents generated by biofilms was more pronounced. The current density of the S. aureus biofilm was 0.9‧10−7 A cm−2, while the value of the P. aeruginosa biofilm was 1.3‧10−6 A cm−2. Importantly, a biofilm formed by a co-culture of S. aureus and P. aeruginosa had a slightly higher negative OCP value and current density than the most electrogenic P. aeruginosa single-species biofilm. We present evidence that bacteria can share redox mediators found in multi-species biofilms. This synergy, enabling higher current and OCP values of multi-species biofilm hosting electrodes, could be beneficial for electrochemical detection of infectious biofilms in clinics. We demonstrate that the electrogenic biofilm can provide basis to construct novel wireless, chip-free, and battery-free biofilm detection method.
|
|
| 3. |
- Žalnėravičius, Rokas, et al.
(författare)
-
Nanoplatelet MoS2 arrays decorated with Pt nanoparticles for non-enzymatic detection of hydrogen peroxide
- 2019
-
Ingår i: Journal of Electroanalytical Chemistry. - : Elsevier. - 1572-6657. ; 839, s. 274-282
-
Tidskriftsartikel (refereegranskat)abstract
- An electrochemical detection platform for monitoring of hydrogen peroxide was designed based on molybdenum disulphide nanocomposites. Bulk MoS2 as well as flower-like MoS2 sheets on Ti substrate were synthesized via a hydrothermal approach. Monodispersed MoS2 nanoparticles with average size less than 2 nm were fabricated by simple and low-cost ultrasonication and gradient centrifugation method. The MoS2/Ti structures were further assessed for amperometric H2O2 detection. The nanoflower MoS2/Ti electrode were electrochemically designed with highly dense Pt nanoparticles. The structure and surface morphology were subsequently characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques. The electrochemical behaviours and sensing performances of the MoS2/GC, MoS2/Ti and Pt/MoS2/Ti electrodes were studied by cyclic voltammetry (CV) and chronoamperometry. The MoS2 nanoparticle modified GC electrode displayed excellent sensitivity towards H2O2 at applied voltage of -0.6 V and the best sensitivity of 1.93 mu A mu M-1 cm(-2) was reached with Pt/MoS2/Ti electrodes. The electrodes prepared by using novel hybrid MoS2 nanomaterials showed high sensitivity, selectivity and long-term stability (at least 10 days) for monitoring of H2O2 and, thus, deserve further studies of their application in development of sensors and biosensors.
|
|
