μstat 400

¹H-NMR and ¹³C-NMR spectra were recorded on a Bruker multidimensional 400 MHz spectrometer, using the solvent or the TMS signal as an internal standard. All chemical shifts are reported in the standard δ notation of parts per million. EPR spectra were recorded in the X band (9.80 GHz) using a Bruker ECS 106 spectrometer with a rectangular cavity and 50 KHz field modulation. Absorption spectra were recorded at 25°C using a Perkin Elmer model Lambda 11 spectrometer. Voltammograms were obtained using a potentiostat DropSens μStat 400. To perform this analysis, 7.5 mL of ultrapure water, 0.5 mL Phosphate-buffered saline, pH 3.0 or 6.8, and 0.25 mL of 1.54 mM CT51 were added to the electrochemical cell. After a resting time of 3 s, the voltammograms were performed at a scan rate of 100 mV s^-1.

A DropSens μStat 400 potentiostat/galvanostat with Dropview, a software made in Spain, was used for electrochemical studies. To characterize the nano-flowers by field emission scanning electron microscopy (FESEM), a Hitachi S4160 and an EDS EDAX/AMETEK element, made in Japan, a Rigaku UltimaIV X-ray diffractometer (XRD), made in Japan, and a Bruker spectrum Fourier-transform infrared spectrometer (FT-IR), made in the United States of America, were used. In addition, a 2 mm glassy carbon electrode, an Ag/AgCl/KCl (3.0 mol/L) electrode made by Azar Electrode, Iran and a 2 mm mechanical B₂ pencil lead made in China were used as a working, reference and auxiliary electrode, respectively.

Voltammetric measurements were conducted in a conventional glass cell using an μSTAT 400 potentiostat controlled by DropView 8400 software (DropSens, Oviedo, Spain). A three-electrode setup was used, consisting of a working glassy carbon (GC) electrode with an active surface of 5 mm diameter, a platinum counter electrode and a Ag/AgCl (3 M KCl) reference electrode, chemically isolated from the test solution with a porous Vycor frit (Metrohm Autolab B.V., Utrecht, The Netherlands). A boron-doped diamond (3 mm diameter, BDD, Windsor Scientific Ltd., Slough, UK) and disposable screen-printed carbon paste (SP-CP, model DRP-110, 4 mm diameter, DropSens, Oviedo, Spain) were also used as working electrodes.
The UHPLC system consisted of a 1290 Infinity LC system equipped with an auto-sampler, a degasser, a quaternary pump, a column thermostat and a diode array detector (DAD) operating at 273 nm. A Kinetex XB-C18 2.1 mm × 100 mm, 2.6 μm column (Phenomenex Torrance, CA, USA) was used at room temperature. For the analysis of the chromatograms, LC OpenLab was used. All equipment was purchased from Agilent Technologies (Waldbronn, Germany).

The electrochemical measurements were conducted using Dropsens screen printed electrodes (DRP-110) in a DropSens μStat400 potentiostat. For sample preparation, 0.01 g of PANI was dispersed in 5 mL of NMP. Then, 2 μL of each solution were drop-casted onto the carbon working electrode and dried under vacuum. The electrolyte employed was 1 M HCl.