title: Rational design for enhancing inflammation-responsive in vivo chemiluminescence via nanophotonic energy relay to near-infrared AIE-active conjugated polymer.
abstract: H2O2-specific peroxalate chemiluminescence is recognized as a potential signal for sensitive in vivo imaging of inflammation but the effect of underlying peroxalate-emitter energetics on its efficiency has rarely been understood. Here we report a simple nanophotonic way of boosting near-infrared chemiluminescence with no need of complicated structural design and synthesis of an energetically favored emitter. The signal enhancement was attained from the construction of a nanoparticle imaging probe (∼26 nm in size) by dense nanointegration of multiple molecules possessing unique photonic features, i.e., i) a peroxalate as a chemical fuel generating electronic excitation energy in response to inflammatory H2O2, ii) a low-bandgap conjugated polymer as a bright near-infrared emitter showing aggregation-induced emission (AIE), and iii) an energy gap-bridging photonic molecule that relays the chemically generated excitation energy to the emitter for its efficient excitation. From static and kinetic spectroscopic studies, a green-emissive BODIPY dye has proven to be an efficient relay molecule to bridge the energy gap between the AIE polymer and the chemically generated excited intermediate of H2O2-reacted peroxalates. The energy-relayed nanointegration of AIE polymer and peroxalate in water showed a 50-times boosted sensing signal compared to their dissolved mixture in THF. Besides the high H2O2 detectability down to 10(-9) M, the boosted chemiluminescence presented a fairly high tissue penetration depth (>12 mm) in an ex vivo condition, which enabled deep imaging of inflammatory H2O2 in a hair-covered mouse model of peritonitis.
authors.affiliation: Center for Theragnosis, Korea Institute of Science and Technology (KIST), 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791, Republic of Korea; Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemungu, Seoul 120-749, Republic of Korea.
authors.forename: Young Hun
authors.initials: YH
authors.lastname: Seo
authors.affiliation: Center for Theragnosis, Korea Institute of Science and Technology (KIST), 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791, Republic of Korea.
authors.forename: Ajay
authors.initials: A
authors.lastname: Singh
authors.affiliation: Center for Theragnosis, Korea Institute of Science and Technology (KIST), 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791, Republic of Korea.
authors.forename: Hong-Jun
authors.initials: HJ
authors.lastname: Cho
authors.affiliation: Center for Theragnosis, Korea Institute of Science and Technology (KIST), 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791, Republic of Korea.
authors.forename: Youngsun
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Center for Theragnosis, Korea Institute of Science and Technology (KIST), 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791, Republic of Korea; Department of Material Science and Engineering, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-744, Republic of Korea.
authors.forename: Jeongyun
authors.initials: J
authors.lastname: Heo
authors.affiliation: Center for Theragnosis, Korea Institute of Science and Technology (KIST), 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791, Republic of Korea.
authors.forename: Chang-Keun
authors.initials: CK
authors.lastname: Lim
authors.affiliation: Department of Material Science and Engineering, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-744, Republic of Korea.
authors.forename: Soo Young
authors.initials: SY
authors.lastname: Park
authors.affiliation: Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemungu, Seoul 120-749, Republic of Korea.
authors.forename: Woo-Dong
authors.initials: WD
authors.lastname: Jang
authors.affiliation: Center for Theragnosis, Korea Institute of Science and Technology (KIST), 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791, Republic of Korea. Electronic address: sehoonkim@kist.re.kr.
authors.forename: Sehoon
authors.initials: S
authors.lastname: Kim
mesh_terms: D000818:Animals; D007249:Inflammation / Q000473:pathology*; D008163:Luminescent Measurements / Q000379:methods*; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D053758:Nanoparticles / Q000737:chemistry*; D010070:Oxalates / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared
chemical_list: D010070:Oxalates; D011108:Polymers
keywords: AIE-active conjugated polymer; Chemiluminescence; Hydrogen peroxide; Inflammation; Nanoparticles