Diamond B23 CD Imaging of Thin Films of Chiral Materials or Achiral Polymers Coated with Chiral Molecules

Rohanah Hussain,Harini Sriram,Charlotte S Hughes,Tamás Jávorfi,Giuliano Siligardi,Rajamani Lashminarayanan

doi:10.3390/sym12111847

Rohanah Hussain, Harini Sriram + Show 4 more

Open Access

https://doi.org/10.3390/sym12111847

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Journal: Symmetry	Publication Date: Nov 9, 2020
Citations: 4	License type: CC BY 4.0

Affiliation: Diamond Light Source, Singapore Eye Research Institute

Abstract

The novel vertical sample chamber, developed at the B23 beamline for synchrotron radiation circular dichroism (SRCD), has enabled the Diamond User community to conduct different types of experiments from high throughput CD of protein and DNA folding using 96-well multiplates to CD imaging at high spatial resolution. Here, we present the application of CD imaging to large areas of achiral polymer PVA films doped with D-dopa to assess the chiral homogeneity of the film preparation with potential antimicrobial property. Synopsis: CDi application of Diamond B23 SRCD beamline.

Highlights

Beamline B23 at Diamond Light Source Ltd., UK, is a bending magnet beamline dedicated to circular dichroism to study, in particular, the structure and function of biological macromolecules [1,2]
The chamber includes a motorised sample stage that enables the positioning of the object of interest, from cuvette cells to 96-well multiplates to thin films held in the optical path, with high precision and repeatability (Figure 1B)
The highly collimated nature of the micro beamlight produced by the B23 beamline [3,4,5,6,7] enables the incident light to pass through the double grating subtractive monochromator, the linear polariser, the photoelastic modulator (PEM), the 10× objective lens, and the sample, reaching the photomultiplier tube (PMT) detector (Figure 1A)

Summary

Introduction

Beamline B23 at Diamond Light Source Ltd., UK, is a bending magnet beamline dedicated to circular dichroism to study, in particular, the structure and function of biological macromolecules [1,2].The beamline can deliver in excess of 1 × 1012 photons/s/0.1% bw(bandwidth) at 6.2 eV (200 nm), with Diamond operating at 300 mA ring current into a focal spot size in the order of 0.5 mm2 (Figure 1A)to either of two independent end stations (Modules A and B), which together span the 125–650 nm wavelength range. All CD mapping was conducted by scanning SRCD spectra in a rastering manner by starting at the bottom left corner at the Symmetry 2020, 12, 1847 coordinates of the 1st row and 1st column of the chosen grid and moving the sample to the right for the chosen interval value until reaching the coordinate of the 1st row and last column.

Results

Conclusion