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

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. First IR-SNOM images over the Amide I band taken in the centre of an oesophageal cancer cell.