Leo 155 gemini

The morphology and structure of the GPE were characterized by a scanning electron microscope (SEM, LEO 155 Gemini, Zeiss, Germany) and energydispersive X-ray spectroscopy (EDS, Oxford Instruments, Abingdon, UK). Raman spectra were acquired with a LabRAM HR 800 Raman spectrometer (Horiba Jobin Yvon, Palaiseau, France) using a 660 nm laser with a power of 5 mW. The electrochemical measurements were performed by a BiPotentiostat/galvanostat μStat400 (Metrohm DropSens, S.L., Asturias, Spain). The electrochemical properties of the electrodes were characterized in 0.1 mol L⁻¹ KCl containing 2 mmol L⁻¹ [Fe(CN)₆]^3−/4− and through cyclic voltammetry. Serum samples were obtained from a diabetes patient at Hatyai Hospital, Hat Yai, Songkhla, Thailand.

The electrode morphology
was characterized by a scanning electron
microscope (SEM, LEO 155 Gemini, Zeiss, Germany). The element composition
and mapping were determined by energy-dispersive X-ray spectroscopy
(EDS, Oxford Instruments). Raman spectra were acquired with a LabRAM
HR 800 Raman spectrometer (Horiba Jobin Yvon, France) using a 660
nm laser with a power of 5 mW.
All of the electrochemical measurements
were performed by a BiPotentiostat/galvanostat μStat400 (Metrohm
DropSens, S.L., Spain) at room temperature in an electrochemical cell
consisting of a platinum wire, a silver/silver chloride (Ag/AgCl)
electrode, and carbon paper as an auxiliary electrode, a reference
electrode, and a working electrode, respectively. Electrochemical
impedance spectroscopy was performed in 0.1 M KCl solution containing
5 mM [FeCN₆]^3–/4– over the frequency
range of 100 kHz–0.01 Hz with a voltage amplitude of 5 mV.
The impedance spectra were then analyzed with ZSimpWin Software (AMETEK
Scientific instruments).