Water‐Dispersable Silica‐Supported Nanocrystalline Pb‐Free Perovskite Rb₇Bi₃Cl₁₆@SiO₂ for ATP‐Responsive Bio‐Imaging

Abstract

Lead‐free perovskite nanocrystal has attracted more and more attention due to its low toxicity and highly luminescence, however, its low stability in water and biotoxicity greatly limits its practical application in sensing in aqueous media, especially, biological imaging. Herein, we develop water‐dispersed Bi‐based perovskite nanocrystals (NCs) coated with SiO2, namely, Rb7Bi3Cl16 NCs@SiO2, where Rb7Bi3Cl16 NCs@SiO2 powder could be obtained through a simply mixing Rb7Bi3Cl16 nanocrystals dispersed in toluene and 3‐aminopropyltriethoxysilane (APTES). Comparison with Rb7Bi3Cl16 nanocrystals (NCs), the photoluminescence (PL) spectra of the Rb7Bi3Cl16 NCs@SiO2 dispersed in water is slight red‐shifted to 445 nm; in addition, its PL quantum yield (PLQY) is increased from 28.43 % of Rb7Bi3Cl16 NCs to 37.03 % owing to the surface passivation and coating of SiO2 from the hydrolysis of APTES. Therefore, this water‐stable, highly luminescent and low‐cytotoxic Rb7Bi3Cl16 NCs@SiO2 nanoparticles can be applied to cell imaging. Furthermore, the tannic acid modified Rb7Bi3Cl16 NCs@SiO2 exhibits adenosine‐5′‐triphosphate disodium salt (ATP) response performance, indicating its potential application in bio‐imaging and biomedicine.