Execution Stage 1

Title: Fabrication of the rough flexible PDMS electrochemical substrate and final plasmonic electrochemical PDMS chip

Period: April - December 2022

Main Results: 

i) Fabrication of the polydimethylsiloxane (PDMS) substrate and modification of its micro-roughness by the controlled imprint of the 3D filter paper matrix on the substrate's surface;

ii) Fabrication of various designs of electrode arrays using self-made paper-based negative molds onto the surface of the PDMS substrate via the thermal deposition process;

iii) Successful chemical synthesis and characterization of aqueous gold nanobipyramids' (AuBPs) colloidal solutions with different aspect ratios showing Localized Surface Plasmon Resonances (LSPR) spanning from 670 to 941 nm;

iv) Functionalization of the working electrode to efficiently deposit the gold nanobipyramids and evaluation of its Surface Enhanced Raman  Spectroscopy (SERS) detection capabilities using a well-known Raman reporter;

v) Fabrication of the polyvinyl alcohol (PVA) porous membrane that ensures the sweat transport to the AuBPs-coated working electrode and successful assembly of the final plasmonic electrochemical PDMS chip;

vi) Creation of the designated webpage of the Chip4GluDet project. 

Execution Stage 2

Title: Testing of the chip as an enzymatic glucose biosensor in laboratory conditions 

Period: January - December 2023

Main Results: 

i) Functionalization of the AuBPs-WE electrode with glucose biorecognition molecules;

ii) Preparation of the artificial sweat containing different glucose concentrations for glucose detection in simulated conditions;

iii) Successful detection of glucose in both laboratory and simulated conditions via SERS sensing;

iv) Optimization of the electrode array in order to obtain a stable and reproducible electrochemical signal by fabricating a silver RE using the same fabrication process;

vi) Update of the designated webpage of the Chip4GluDet project. 

Execution Stage 3

Title: Validation of the chip as an enzymatic glucose biosensor in laboratory and simulated conditions 

Period: January - March 2024

Main Results: 

i) Functionalization of the AuBPs-WE electrode for the enzymatic recognition interaction;

ii) Successful non-enzymatic detection of glucose in both laboratory and simulated conditions via electrochemical sensing;

iii) Successful enzymatic detection of glucose in both laboratory and simulated conditions via SERS sensing;

vi) Update of the designated webpage of the Chip4GluDet project and dissemination of the project's results.