Multimode nanoscope iva

Voltammetric measurements, such as cyclic voltammetry (CV) and square wave voltammetry (SWV), were carried out using an Autolab PGSTAT10 potentiostat/galvanostat controlled by GPES 4.9 software. Electrochemical impedance spectroscopy (EIS) studies were performed using an Autolab PGSTAT204 potentiostat/galvanostat expanded with a FRA32M EIS module (Metrohm, Herisau, Switzerland) and the NOVA 1.10.1.9 software for data acquisition. Fitting of the EIS data was performed with EIS Spectrum Analyser 1.0 [64 ].
Commercial SPCEs consisting of a carbon working electrode modified with carboxyl functionalized MWCNT (SPCE-MWCNT) with a 4.0 mm diameter, a carbon auxiliary electrode and a silver (Ag) pseudo-reference electrode (DropSens, Llanera, Spain, ref. 110CNT) were used to prepare the electrochemical sensors.
The electrodes’ surfaces were examined by atomic force microscopy (AFM) using a scanning probe microscope (SPM) operating on atomic force, magnetic force and scanning tunnel microscopy Veeco Metrology Multimode/Nanoscope IVA, and by scanning electron microscopy (SEM) using a high-resolution scanning electron microscope with X-ray microanalysis Quanta 400 FEG ESEM/EDAX Pegasus X4M (FEI, Hillsboro, OR, USA), at the CEMUP Laboratory (University of Porto, Porto, Portugal).

The electrochemical measurements were conducted with a potentiostat/galvanostat from Metrohm Autolab and a PGSTAT302N, equipped with a FRA2 module and controlled by Nova 10.1 software. Raman measurements were performed using a Thermo Scientific DXR Raman microscope system with a 100 mW 532 nm excitation laser. Ellipsometry measurements were performed using a J.A.Woollam Co, Inc M/2000V model ellipsometer with a 370–1000 nm spectral range and 50 W QTH lamp equipped with an EC/400 electronics control module and controlled with CompleteEASE v4.92 software. Atomic force microscopy (AFM) measurements were performed using Veeco Metrology Multimode/Nanoscope IVA. Au-SPEs were purchased from DROPSENS (DRP-C220AT), having working and counter electrodes made of gold and reference electrode and electrical contacts made of silver. The diameter of the working electrode was 4 mm. The Au-SPEs were interfaced with the potentiostat by means of a compatible switch box, from BioTID/Porto-Portugal.

Zeta potential measurements were determined by using a particle analyzer Anton Paar Litesizer™ 500. X-ray photoelectron spectroscopy (XPS) data were obtained with a Fi Kratos Axis Ultra HAS-VISION. AFM analysis was carried out using a Veeco Metrology Multimode/Nanoscope IVA by tapping. A silica plate was used to deposit the sample for analysis and an AFM RTESP cantilever was used. UV–Vis spectra were obtained with a UV-3100PC spectrophotometer, by using quartz cells. Fluorescence spectra were obtained in standard 10 mm fluorescence quartz cells and collected in a Horiba Jovin Yvon Fluoromax-4 spectrofluorimeter. Spectra were obtained with a 1 nm interval and 5 nm slit widths. The assessment of photostability was made by subjecting CDs to irradiation by a low-pressure lamp (40 W, model Vilber, VL-340.BL) emitting UV radiation at 365 nm.