Original data of porous microneedle-based biosensor for dry eye disease

Unmodified Au WE surface was analyzed with energy dispersive X-ray spectroscopy (EDS) on the same equipment.The morphology of MN was imaged with field-emission scanning electron microscope (SEM) (FEI Quanta 250). The needles were cut and removed from the base, while the MN base was cut perpendicularly to reveal the internal structures. All samples were sputter coated with a 10-nm gold layer for SEM imaging.Surface-enhanced Raman spectroscopySurface-enhanced Raman spectroscopy was done using WiTec Raman System at an excitation wavelength of 633 nm.

A large area scan was carried out on the surface of the aptamer modified WE (20 × 20 μm) with 20 points per line, 20 lines per image, and an integration time of 3 s. The resulting data and images were processed using WiTec Project 5.1.Sensor characterization All electrochemical measurements were done with CHI 760E electrochemical analyzer workstation. All measurements were carried out in 5 mM ferri/ferrocyanide (Fe(CN)63-/4-) buffer with 0.1 M potassium chloride (KCl) and 0.1 M potassium nitrate (KNO3).

Cyclic voltammetry (CV) was carried out from -1 V to 1 V, a scan rate of 0.1 V/s, and 10-4 A sensitivity on the same sensor before and after cleaning with mild “piranha” solution, after the addition of aptamer and after incubation in MCH. Electrochemical impedance spectroscopy (EIS) was completed as well for the same electrode modification steps on one sensor under the parameters of 0.1 to 100000 Hz and a 0.005 V amplitude.

SWV at 60 Hz and 40mV amplitude over -0.05 V to 0.35 V was done on bare electrodes, as well as after aptamer-MCH modification and after addition of target biomarker on the same sensor.