Enzymatic enhancing of triplet–triplet annihilation upconversion by breaking oxygen quenching for background-free biological sensing

• Published in: Nature communications Vol. 12; no. 1; pp. 1898 - 9
• Main Authors: Huang, Ling, Le, Timmy, Huang, Kai, Han, Gang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 26.03.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 639/925/357/354; 639/925/927/59; 9/10; Algorithms; Aqueous solutions; Catalysis - radiation effects; Depletion; Energy harvesting; Glucose; Glucose - metabolism; Glucose oxidase; Glucose Oxidase - metabolism; Humanities and Social Sciences; Humans; Light; Metabolism; Models, Chemical; Molecular Structure; multidisciplinary; Nanoparticles; Nanoparticles - chemistry; Nanoparticles - radiation effects; Organic chemistry; Oxidation; Oxidation-Reduction - radiation effects; Oxygen; Oxygen - chemistry; Oxygen - metabolism; Oxygen depletion; Quenching; Science; Science (multidisciplinary); Sensors; Solar energy; Spectrometry, Fluorescence; Upconversion; Water - chemistry
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-22282-1

Triplet-triplet annihilation upconversion nanoparticles have attracted considerable interest due to their promises in organic chemistry, solar energy harvesting and several biological applications. However, triplet-triplet annihilation upconversion in aqueous solutions is challenging due to sensitivity to oxygen, hindering its biological applications under ambient atmosphere. Herein, we report a simple enzymatic strategy to overcome oxygen-induced triplet-triplet annihilation upconversion quenching. This strategy stems from a glucose oxidase catalyzed glucose oxidation reaction, which enables rapid oxygen depletion to turn on upconversion in the aqueous solution. Furthermore, self-standing upconversion biological sensors of such nanoparticles are developed to detect glucose and measure the activity of enzymes related to glucose metabolism in a highly specific, sensitive and background-free manner. This study not only overcomes the key roadblock for applications of triplet-triplet annihilation upconversion nanoparticles in aqueous solutions, it also establishes the proof-of-concept to develop triplet-triplet annihilation upconversion nanoparticles as background free self-standing biological sensors. Triplet-triplet annihilation upconversion (TTA-UC) nanoparticles (NPs) are a promising material for diverse applications, but TTA-UC is sensitive to oxygen, which hinders its biological utility. Here, the authors report an enzymatic method to deplete oxygen and amplify the upconversion of TTA-UCNP in aqueous solution, and develop background-free glucose and glucose metabolism enzyme sensors.