The far-field optical imaging of mitochondria of live cells without the use of any label is demonstrated. It uses a highly sensitive photothermal method and has a resolution comparable to confocal fluorescence setups. The morphological states of mitochondria were followed under different physiological treatments, and the role of cytochrome c was ruled out as the main origin of the photothermal ...

The object reconstruction from synthesized and noisy photothermal signals was carried out by deconvoluting contrast scans by means of photothermal point spread function. The unknown defect depth parameter was estimated by minimizing the "imaginary content" of the deconvoluted real valued defect distribution. The algorithm shows remarkable accuracy even in the presence of 10%-noise in finding th...

BACKGROUND AND OBJECTIVES In theory, infrared vibrational bands could be used for selective photothermolysis of lipid-rich tissues such as fat, sebaceous glands, or atherosclerotic plaques. STUDY DESIGN/MATERIALS AND METHODS Absorption spectra of human fat were measured, identifying promising bands near 1,210 and 1,720 nm. Photothermal excitation of porcine fat and dermis were measured with a...

Skin cancer is one of the most common cancers. Melanoma accounts for less than 2% of skin cancer cases but causes a large majority of skin cancer deaths. Early detection of malignant melanoma remains the key factor in saving lives. However, the melanoma diagnosis is still clinically challenging. Here, we developed a confocal photothermal microscope for noninvasive, label-free, three-dimensional...

In this study, we developed a nanosystem based on upconversion nanoparticles (UCNPs) coated with a layer of polyaniline nanoparticles (PANPs). The UCNP induces upconversion luminescence for imaging and photothermal conversion properties are due to PANPs. In vitro experiments showed that the UCNPs-PANPs were nontoxic to cells even at a high concentration (800 µg mL(-1)). Blood analysis and histo...

We evaluate a method for biofilm disinfection by raising biofilm temperature using the photothermal effect of a gold nanorod cluster. Gold nanorods (GNRs) are capable of generating enough heat to lyse bacteria by heating biofilm via laser irradiation. To test this, GNRs are synthesized using wet chemistry and a single GNR cluster is fabricated using photo-lithography technique. The GNR cluster ...

Photothermal excitation is an alternative cantilever drive mechanism for tapping mode atomic force microscopy. It uses a power-modulated laser focused on the cantilever to directly drive its oscillation, producing cantilever tunes that match the thermal response almost perfectly. This enables quantitatively accurate AFM imaging and viscoelastic nanomechanical mapping in all environments. In add...

A fast, high-sensitivity photothermal microscope was developed by implementing a spatially segmented balanced detection scheme into a laser scanning microscope. We confirmed a 4.9 times improvement in signal-to-noise ratio in the spatially segmented balanced detection compared with that of conventional detection. The system demonstrated simultaneous bi-modal photothermal and confocal fluorescen...

We present a novel gold bellflower (GBF) platform with multiple-branched petals, prepared by a liquid-liquid-gas triphase interface system, for photoacoustic imaging (PAI)-guided photothermal therapy (PTT). Upon near-infrared (NIR) laser irradiation, the GBFs, with strong NIR absorption, showed very strong PA response and an ultrahigh photothermal conversion efficiency (η, ∼74%) among the repor...

Abstract: Photothermal radiometry is an infrared remote sensing technique that has been used for skin and skin appendages research, in the areas of skin hydration, hydration gradient, skin hydration depth profiling, skin thickness measurements, skin pigmentation measurements, effect of topically applied substances, transdermal drug delivery, moisture content of bio-materials, membrane permeatio...