摘要
For the first time, we are reporting a novel type of dual fluorescence temperaturesensitive DNA-templated silver nanocluster （AgNC） pair, which contains two pieces of single-stranded AgNC in proximity through hybridization. Both the chameleon AgNC pairs, A-NCP and B-NCP, possess two bright fluorescence peaks that achieve sensitive variations corresponding to temperature change from 15 to 45 ℃. With the increase in temperature, one of the fluorescence emissions of A-NCP （A-FL570） increases, while the other （A-FL640） decreases. However, both the emissions of B-NCP （B-FL685 and B-FL620） decrease simultaneously. Therefore, A-NCP shows a remarkable fluorescence color variation from orange to yellow, while the fluorescence color of B-NCP changes from orange to colorless, with increase in temperature. Moreover, the temperature responding linear range of A-NCP can be regulated by adjusting the structures and sequences of assistant DNA templates. It is assumed that the two single-stranded segmental AgNCs are integrated together as they are assembled into AgNC pairs, leading to a dramatic variation in fluorescence properties. The temperature-sensitive phenomenon is due to the dehybridization-induced separation of two pieces of segmental AgNC, caused by temperature increase. The temperature-sensitive AgNC pairs have been successful in indicating the temperature of living cells, showing the potential for a new application of silver nanocluster as a nanothermometer with adjustable response range, bringing novel insight into the regulatory mechanism of AgNC fluorescence variation.
For the first time, we are reporting a novel type of dual fluorescence temperaturesensitive DNA-templated silver nanocluster （AgNC） pair, which contains two pieces of single-stranded AgNC in proximity through hybridization. Both the chameleon AgNC pairs, A-NCP and B-NCP, possess two bright fluorescence peaks that achieve sensitive variations corresponding to temperature change from 15 to 45 ℃. With the increase in temperature, one of the fluorescence emissions of A-NCP （A-FL570） increases, while the other （A-FL640） decreases. However, both the emissions of B-NCP （B-FL685 and B-FL620） decrease simultaneously. Therefore, A-NCP shows a remarkable fluorescence color variation from orange to yellow, while the fluorescence color of B-NCP changes from orange to colorless, with increase in temperature. Moreover, the temperature responding linear range of A-NCP can be regulated by adjusting the structures and sequences of assistant DNA templates. It is assumed that the two single-stranded segmental AgNCs are integrated together as they are assembled into AgNC pairs, leading to a dramatic variation in fluorescence properties. The temperature-sensitive phenomenon is due to the dehybridization-induced separation of two pieces of segmental AgNC, caused by temperature increase. The temperature-sensitive AgNC pairs have been successful in indicating the temperature of living cells, showing the potential for a new application of silver nanocluster as a nanothermometer with adjustable response range, bringing novel insight into the regulatory mechanism of AgNC fluorescence variation.
基金
This work was supported by National Natural Science Foundation of China （No. 21375123） and The Ministry of Science and Technology of China （No. 216YFA0203201）.
