Bk d590

To investigate the bio-reductive properties of Swertia chirata leaf extracts and their ability to form AgNPs, a BioBase BK-D590 double-beam UV–visible spectrophotometer with a wavelength range of 190 nm–1100 nm was employed [28 ]. Optical density (OD) measurements were recorded to confirm the reduction of silver nitrate during the process.
The elemental analysis of the green synthesized nanoparticles was performed with an EDX (model: OXFORD_INCA PENTx3) and recorded with an electronic microscope (model: JEOL JSM 5410).
The morphological characteristics of biosynthesized silver nanoparticles produced from plant extract have been studied using SEM. After adding AgNO3 for 48 h, the solutions were spread out on slides to create the SEM samples. To make the samples conductible, a thin coating of platinum was applied to them. Following that, the samples were characterized in the SEM using a 20 kV accelerating voltage.

The current pulse provided to LED sources was measured through the integrated output of the DLD, whereas the emitted optical pulses were characterized using a Si-based photodiode (DET36A, Thorlabs, Newton, NJ, USA; rise/fall time: 14 ns). All data were recorded by the digital oscilloscope of the PA system (NI USB-5133). The emission spectra of LEDs were determined by a spectrograph (getSpec 2048, getAmo, Sofia, Bulgaria) using 1 nm wavelength steps. The average power of the LEDs during the pulsed operation was measured using a sensitive thermal power sensor head (S405C, Thorlabs, Newton, NJ, USA) connected to a USB power meter interface (PM100USB, Thorlabs, Newton, NJ, USA). For each measurement, the sensor head was placed at the bottom of an empty sample container, with its front side facing directly the 10 mm diameter circular window. In every case, the LED was positioned at a fixed distance below the surface of the coverslip glass. The two LED sources operated one at a time, and were placed at identical positions to achieve similar illumination conditions on the phantoms. The optical power on the sample was controlled using a set of neutral density filters (NDK01, Thorlabs, Newton, NJ, USA). Absorption spectra of phantom samples were measured by a UV-VIS spectrophotometer (BK-D590, Biobase, Jinan, China) using 1 cm path plastic cuvettes and a wavelength step of 1 nm.