Interaction of Water-Soluble CdTe Quantum Dots with Bovine Serum Albumin

Semiconductor nanoparticles (quantum dots) are promising fluorescent markers, but it is very little known about interaction of quantum dots with biological molecules. In this study, interaction of CdTe quantum dots coated with thioglycolic acid (TGA) with bovine serum albumin was investigated. Steady state spectroscopy, atomic force microscopy, electron microscopy and dynamic light scattering methods were used. It was explored how bovine serum albumin affects stability and spectral properties of quantum dots in aqueous media. CdTe–TGA quantum dots in aqueous solution appeared to be not stable and precipitated. Interaction with bovine serum albumin significantly enhanced stability and photoluminescence quantum yield of quantum dots and prevented quantum dots from aggregating

Protein stabilized Au nanoclusters: spectral properties and photostability

Bovine serum albumin stabilized gold nanoclusters (BSA-Au nanoclusters) have been widely studied due to their possible applications in biomedicine as sensors, fluorescent or multi-modality markers, and therapeutic agents. Synthesis and optical properties of these nanoclusters have been extensively investigated; however, there is still very little data on photostability of BSA-Au nanoclusters. Photostability of BSA-Au nanoclusters is of major importance for a variety of applications, such as material sensing and fluorescence imaging. Herein we demonstrate that after synthesis the BSA-Au solution has two photoluminescence (PL) bands peaking at 468 and 660 nm. Nevertheless, a different behaviour of the PL bands at 468 and 660 nm upon irradiation indicates that only band at 660 nm is related to PL of Au nanoclusters. BSA-Au nanoclusters exhibit great colloidal stability and do not undergo irreversible changes when heated up to 65 °C. However, irradiation of BSA-Au nanoclusters causes a wavelength dependent decrease of intensity and a hypsochromic shift of the PL band at 660 nm which is proportional to the delivered dose. The shift of the PL band at 660 nm could occur due to loss of several gold atoms in Au nanoclusters and/or due to deterioration of a nanoparticle coating layer. We have also demonstrated that the photostability of BSA-Au nanoclusters increases in the cell growth medium.</jats:p

Blood Plasma Stabilized Gold Nanoclusters for Personalized Tumor Theranostics

Personalized cancer theranostics has a potential to increase efficiency of early cancer diagnostics and treatment, and to reduce negative side-effects. Protein-stabilized gold nanoclusters may serve as theranostic agents. To make gold nanoclusters personalized and highly biocompatible, the clusters were stabilized with human plasma proteins. Optical properties of synthesized nanoclusters were investigated spectroscopically, and possible biomedical application was evaluated using standard cell biology methods. The spectroscopic investigations of human plasma proteins stabilized gold nanoclusters revealed that a wide photoluminescence band in the optical tissue window is suitable for cancer diagnostics. High-capacity generation of singlet oxygen and other reactive oxygen species was also observed. Furthermore, the cluster accumulation in cancer cells and the photodynamic effect were evaluated. The results demonstrate that plasma proteins stabilized gold nanoclusters that accumulate in breast cancer cells and are non-toxic in the dark, while appear phototoxic under irradiation with visible light. The results positively confirm the utility of plasma protein stabilized gold nanoclusters for the use in cancer diagnostics and treatment

Blood Plasma Stabilized Gold Nanoclusters for Personalized Tumor Theranostics

Personalized cancer theranostics has a potential to increase efficiency of early cancer diagnostics and treatment, and to reduce negative side-effects. Protein-stabilized gold nanoclusters may serve as theranostic agents. To make gold nanoclusters personalized and highly biocompatible, the clusters were stabilized with human plasma proteins. Optical properties of synthesized nanoclusters were investigated spectroscopically, and possible biomedical application was evaluated using standard cell biology methods. The spectroscopic investigations of human plasma proteins stabilized gold nanoclusters revealed that a wide photoluminescence band in the optical tissue window is suitable for cancer diagnostics. High-capacity generation of singlet oxygen and other reactive oxygen species was also observed. Furthermore, the cluster accumulation in cancer cells and the photodynamic effect were evaluated. The results demonstrate that plasma proteins stabilized gold nanoclusters that accumulate in breast cancer cells and are non-toxic in the dark, while appear phototoxic under irradiation with visible light. The results positively confirm the utility of plasma protein stabilized gold nanoclusters for the use in cancer diagnostics and treatment.</jats:p

Aplinkos drėgmės įtaka paviršinių akustinių bangų slopinimui ir greičiui hematoporfirino - LiNbO3 dariniuose

The impact of ambient humidity on a surface acoustic wave (SAW) propagation in the structure consisting of hematoporphyrin (Hp) film deposited on a piezoelectric lithium niobate substrate has been studied. The SAW transmission dependencies on frequency were measured using an RF network analyzer, and the variation in the SAW velocity was measured using SAW delay-line oscillator technique. The increase in the SAW velocity and decrease in the SAW attenuation with increasing ambient humidity was observed. Both dependencies exhibited exponential dependence on a humidity, and the relative velocity change was proportional to the squared change in the attenuation. This observation is in agreement with the conductivity related mechanism of the humidity impact on the SAW propagation parameters in a hematoporphyrin-lithium niobate structure. The results show that Hp - LiNbO3 structure can be used as a SAW humidity sensor