Application of a quantum cascade laser aperture scanning near-field optical microscope to the study of a cancer cell

Abstract

This work reports the first images obtained by combining an infrared aperture scanning near-field optical microscope (SNOM) with a quantum cascade laser (QCL). The future potential of this set-up is demonstrated by a preliminary study on an OE33 human oesophageal adenocarcinoma cell in which the cell is imaged at 1751 cm⁻¹, 1651 cm⁻¹, 1539 cm⁻¹ and 1242 cm⁻¹. In addition to the 1651 cm⁻¹ image, three other images were acquired within the Amide I band (1689 cm⁻¹, 1675 cm⁻¹ and 1626 cm⁻¹) chosen to correspond to secondary structures of proteins. The four images obtained within the Amide I band show distinct differences demonstrating the potential of this approach to reveal subtle changes in the chemical composition of a cell.