A technique for microsecond heating and cooling of a thin (submicron) biological sample

Real-time Thermal Imaging of Microwave Accelerated Metal-Enhanced Fluorescence (MAMEF) Based Assays on Sapphire Plates

In this paper, we describe an optical geometry that facilitates our further characterization of the temperature changes above silver island films (SiFs) on sapphire plates, when exposed to microwave radiation. Since sapphire transmits IR, we designed an optical scheme to capture real-time temperature images of a thin water film on sapphire plates with and without SiFs during the application of a short microwave pulse. Using this optical scheme, we can accurately determine the temperature profile of solvents in proximity to metal structures when exposed to microwave irradiation. We believe that this optical scheme will provide us with a basis for further studies in designing metal structures to further improve plasmonic-fluorescence clinical sensing applications, such as those used in microwave accelerated metal-enhanced fluorescence (MAMEF).

Photothermal responses of individual cells

Photothermal (PT) responses of individual intact cells are studied with a thermal lens dual-laser scheme. A multiparameter model for analysis of PT responses as a function of cell size, structure, and optical properties is suggested and verified experimentally for living cells, red blood cells, lymphocytes, tumor cells (K 562), hepatocytes, and miocytes, by applying pulsed laser radiation at 532 nm for 10-ns duration. PT responses for noninvasive and damaging modes of laser-cell interaction are investigated. It is shown theoretically and experimentally that specific optical and structural features of cells influence the polarity, shape, front, and tail lengths of their PT responses. Common for different cells, features of PT responses are evaluated. It is found that in cells with a highly heterogeneous light-absorbing structure, the PT response of a whole cell differs from that of the local absorbing area. The model suggested allows us to interpret PT responses from single cells and to compare cells in terms of their diameter, degree of spatial heterogeneity of light absorbance, and laser-induced damage thresholds.