Lambda 25 spectrometer

A Perkin Elmer Lambda 25 spectrometer (Shelton, CT, USA) was used to collect the UV–vis absorption spectra between 200 and 800 nm of graphene materials.

MnM2 was synthesized in our laboratory from 4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diacetate, as previously described^{17 (link)}, on kind permission of the patent owner (General Project Ltd., Montespertoli, Italy). The aqueous solutions used in complex synthesis and in potentiometric measurements were deoxygenated by bubbling N₂ to prevent possible oxidation of Mn^II. All new compounds were characterized by elemental analysis and mass spectroscopy. Elemental analyses (C, H, N content) were performed with Perkin-Elmer 2400 CHN elemental analyzer. C, H, N and Mn percentages were within ±0.2% of theoretical value, in keeping with a >95% purity for all compounds). Determination of the Mn content in the complexes was performed using a Varian 720-ES inductively coupled plasma atomic emission spectrometer (ICP-AES). The biological samples were treated as previously reported^{17 (link)} to obtain suitable solutions for the ICP-AES determination of Mn^II content. IR spectra were collected by a IRAffinity-1S Shimadzu instrument. UV-vis spectra were recorded on a Perkin-Elmer lambda 25 spectrometer.

The corresponding oligonucleotides, human telomeric G1 and G2T1, were dissolved in 10 mm Tris‐HCl, pH 7.04, and 100 mm KCl (or NaCl) buffer to yield a 500 μm solution. The oligonucleotide was annealed by heating to 95 °C for 10 min and then cooled to room temperature overnight. The UV/Vis spectra were recorded on a PerkinElmer Lambda 25 spectrometer. To determine the binding constants of the selected complexes with DNA including G2T1, G1, and CT DNA, the complex (20 μm) was titrated with concentrated solutions of DNA (500 μm) in 100 mm KCl (or NaCl) buffer. A 1 cm path‐length quartz cuvette was used to carry out the measurements. The apparent binding constants (K_a values) were obtained by fitting the data to a reciprocal plot of D/Δϵ_ap versus D using the following equation: D/Δϵ_ap=D/Δϵ+1/(Δϵ×K_a).35, 48 The concentration of DNA (D) is expressed in terms of base pairs (determined by measuring the absorption at 260 nm and the appropriate extinction coefficients); the apparent molar extinction coefficient ϵ_a=A_observed/[Complex], Δϵ_ap=[ϵ_a−ϵ_f], and Δϵ=[ϵ_b−ϵ_f]; ϵ_b is the extinction coefficient of the DNA bound complex, and ϵ_f is the extinction coefficient of the free complex.

Films for spectroscopic characterization were spin-coated from polymer/PC70BM solutions (o-dichlorobenzene, 25 mg ml⁻¹) with a weight ratio of 1:2 for SiIDT–2FBT/PC70BM and 1:3 for SiIDT–DTBT/PC70BM under standard conditions. For devices, the same blend compositions and spin-coating conditions were used. Indium–tin-oxide substrates with a sheet resistance of 15 Ωsq⁻¹ (PsioTec Ltd, UK) were first cleaned in detergent, acetone and isopropanol and then oxygen plasma treated for 7 min at 100 W. The substrate was coated with filtered PEDOT:PSS and heated to 150 °C in air for 20 min on a hot plate. The active layer was then spin-coated in air and placed into a nitrogen glove box (<10 p.p.m. O2, H2O), where Ca (25 nm)/Al (100 nm) electrodes were deposited by thermal evaporation under vacuum. Device area was 0.045 cm².
J–V curves were measured with a Keithley 238 source measure unit and a filtered 150-W xenon arc lamp generating simulated AM1.5 conditions (LOT Oriel). A calibrated reference silicon photodiode was used as a reference for the J–V measurements.
Ultraviolet/visible spectra of the thin films were measured with a PerkinElmer Lambda 25 spectrometer in air. The PL spectra were measured with a Fluorolog-3 spectrofluorometer (Horiba Jobin Yvon).

All reagents are purchased and used as received unless stated otherwise. Dry solvents were obtained from solvent purification system (activated alumina columns) (Pure Solv 400-5-MD), apart from chloroform which was purchased from Sigma Aldrich. Mass spectrometry and elemental analysis were obtained from the mass spectrometry service at the University of Glasgow. Melting points (mp) were recorded on a SMP10 Stuart Scientific melting point machine and are uncorrected. ¹H NMR and ¹³C NMR spectroscopy were recorded on Bruker AVIII (400 MHz) spectrometer, operating at 400 MHz and 100 MHz, respectively. Chemical shifts are given in ppm and are relative to TMS, all J values are in Hz. UV-Vis measurements were carried out using a Perkin Elmer Lambda 25 spectrometer. Square wave voltammetry was recorded at room temperature under nitrogen on CH-instruments 440A potentiostat using a three electrodes cell with a platinum (Pt) working electrode, a Pt wire counter electrode and an Ag wire pseudo reference electrode. Samples were analyzed at 1.0 mM concentrations with a scan rate of 0.1 V s⁻¹ using TBAPF₆ (0.1 M in corresponding solvent) as the supporting electrolyte. The reduction potentials are referenced to ferrocene (internal or external reference) with the Fc/Fc⁺ redox couple adjusted to 0.0 V.