Iso no meter

UV/vis absorption spectra were recorded using a Cary UV-Vis spectrophotometer (Agilent Technologies AB, Kista, Sweden). Fluorescence spectra were acquired by fluorescence spectrophotometer (Cary Eclipse, Varian AB, Bromma, Sweden) and a Fluorolog 2 mod F-111 spectrofluorimeter. Spectral measurements were performed with a 2.5% dilution of stock solution 25 mg/mL CPA in 100% DMSO in FBS-free MEM media using quartz cuvette (1 cm path length, 3 mL capacity). Absorption and emission spectra measurements were corrected for solvent background.
NO release after one-photon irradiation was measured by amperometric technique as earlier described^{22 (link)}. In brief a ISO-NO meter (World Precision Instrument) was used by positioning the electrode outside of the light path in thermostated quartz cell (1 cm path length, 3 ml capacity) containing a solution of CPA in H2O:MeOH (1:1). Irradiation was performed 390 nm of the Fluorolog-2 (see above) as light source.

UV–Vis spectra were recorded with a JascoV-560 spectrophotometer (Easton, MD, USA) using either quartz cells with a path length of 1 cm or a specific holder for thin films. Fluorescence emission spectra were recorded with Spex Fluorolog-2 (mod. F-111, Horiba Jobin-Yvon, Japan) in air-equilibrated solutions either in a right angle or in a front face mode for solution or CL samples, respectively.
Direct monitoring of NO release in solution was performed by amperometric detection (World Precision Instruments), with a ISO-NO meter, equipped with a data acquisition system, and based on direct amperometric detection of NO with short response time (<5 s) and sensitivity range 1 nM–20 µM. The analogue signal was digitalized with a four-channel recording system and transferred to a PC. The sensor was accurately calibrated by mixing standard solutions of NaNO₂ with 0.1 M H₂SO₄ and 0.1 M KI according to the reaction:
Irradiation was performed in a thermostated quartz cell (1 cm path length, 3 mL capacity) using the continuum laser with λ_exc = 405 nm. NO measurements were carried out under stirring with the electrode positioned outside the light path in order to avoid NO signal artifacts due to photoelectric interference on the ISO-NO electrode.