Enhancing the quantum yield and Cu2+ sensing sensitivity of carbon dots based on the nano-space confinement effect of silica matrix
Abstract Although the analytical applications of the fluorescent carbon dots (CDs) were widely explored, the development of effective fluorescence signal amplification scheme based on the CDs was challengeable. In this work, we firstly found that, after CDs and polyethyleneimine (PEI) were together doped into silica nanoparticles via a reverse microemulsion route, the CDs inside as-prepared CDs/PEI/silica nanoparticles (CDs/PEI/SiO 2 NPs) presented the higher fluorescence quantum yield and stronger signal amplification ability than that of free-state CDs. Here, the possible fluorescence enhancing mechanism of CDs inside CDs/PEI/SiO 2 NPs was investigated by UV–vis absorption spectra, fluorescence spectra, IR spectra, transmission electron microscope and zeta potential technique and the possible mechanism was also proposed. In addition, the Cu 2+ was selected as the model to investigate the signal amplification feature of the CDs/PEI/SiO 2 NPs. Our results showed that, encapsulation of CDs and PEI into silica NPs lead to a fluorescence enhancement of CDs, the fluorescence quantum yield of CDs increased from 13.7% to 38.6%. The as-prepared CDs/PEI/SiO 2 NPs exhibited 100-times sensitivity increasing for sensing Cu 2+ compared with free-state CDs sensing scheme reported by the previous literature. Highlights Silica matrix selectively reacted with three kinds of amine groups of PEI. Amine groups of PEI densely concentrated inside silica matrix. 3-times quantum yield enhancing by encapsulation of CDs and PEI into silica matrix. The CDs/PEI/SiO 2 NPs presented a 100 times sensitivity increasing for sensing Cu 2+ than free-stated CDs.
유료 다운로드의 경우 해당 사이트의 정책에 따라 신규 회원가입, 로그인, 유료 구매 등이 필요할 수 있습니다. 해당 사이트에서 발생하는 귀하의 모든 정보활동은 NDSL의 서비스 정책과 무관합니다.
원문복사신청을 하시면, 일부 해외 인쇄학술지의 경우 외국학술지지원센터(FRIC)에서
무료 원문복사 서비스를 제공합니다.
NDSL에서는 해당 원문을 복사서비스하고 있습니다. 위의 원문복사신청 또는 장바구니 담기를 통하여 원문복사서비스 이용이 가능합니다.
- 이 논문과 함께 출판된 논문 + 더보기