Hong, A-Ra Han, Joon Soo Kang, Gumin Ko, Hyungduk Jang, Ho Seong 2024-01-19T16:02:46Z 2024-01-19T16:02:46Z 2021-09-02 2020-12 1996-1944 https://pubs.kist.re.kr/handle/201004/117791 In this study, Li-based blue- and green-emitting core@shell (C@S) upconversion nanophosphors (UCNPs) and NaGdF4-based red-emitting C@S UCNPs were synthesized, and IR-808 dyes were conjugated with the C@S UCNPs to enhance upconversion (UC) luminescence. The surface of the as-synthesized C@S UCNPs, which was originally capped with oleic acid, was modified with BF4- to conjugate the IR-808 dye having a carboxyl functional group to the surface of the UCNPs. After the conjugation with IR-808 dyes, absorbance of the UCNPs was significantly increased. As a result, dye-sensitized blue (B)-, green (G)-, and red (R)-emitting UCNPs exhibited 87-fold, 10.8-fold, and 110-fold enhanced UC luminescence compared with B-, G-, and R-emitting Nd3+-doped C@S UCNPs under 800 nm near-infrared (NIR) light excitation, respectively. Consequently, dye-sensitized UCNPs exhibiting strong UC luminescence under 800 nm NIR light excitation have high applicability in a variety of biological applications. English MDPI Bright Blue, Green, and Red Luminescence from Dye-Sensitized Core@Shell Upconversion Nanophosphors under 800 nm Near-Infrared Light Article 10.3390/ma13235338 1 MATERIALS, v.13, no.23 MATERIALS 13 23 scie scopus 000597579900001 2-s2.0-85096719216 Chemistry, Physical Materials Science, Multidisciplinary Metallurgy & Metallurgical Engineering Physics, Applied Physics, Condensed Matter Chemistry Materials Science Metallurgy & Metallurgical Engineering Physics Article upconversion nanophosphors core@shell IR-808 dye dye-sensitized upconversion nanophosphors