摘要
Time-resolved (TR)photoluminescence (PL) technique has shown great promise in ultrasensitive biodetection and high-resolution bioimaging.Hitherto,almost all the TRPL bioprobes are based on the parity-forbidden f→f transition of lanthanide ions.Herein,we report TRPL biosensing by taking advantage of the d→d transition of transition metal (TM)Mn^2+ ion.We demonstrate that the Forster resonance energy transfer (FRET)signal can be distinguished from that of radiative reabsorption process through measuring the PL lifetime of Mn^2+,thus establishing a reliable method for Mn^2+ in homogeneous TR-FRET biodetection.We also demonstrate the biotin receptor-targeted cancer cell imaging by utilizing biotinylated CaF2:Ce,Mn nanoprobes.Furthermore,we show in a proof-of-concept experiment the appli- cation of the long-lived PL of Mn^2+ for TRPL bioimaging through the burst shot with a cell phone.These findings provide a general approach for exploiting the long-lived PL of TM ions for TRPL biosensing,thereby opening up a new avenue for the exploration of novel and versatile applications of TM ions.
时间分辨荧光探测技术在超灵敏生物检测和高分辨生物成像领域具有广泛的应用前景.目前报道的时间分辨荧光生物探针大都是利用稀土离子4fN电子组态间的禁戒跃迁发光.本文报道了基于过渡金属Mn^(2+)离子d→d禁戒跃迁发光的时间分辨荧光生物分析.我们证明通过测试Mn^(2+)的荧光寿命变化可以将荧光共振能量传递与辐射再吸收信号区分开来,从而为Mn^(2+)发光在时间分辨荧光共振能量传递均相生物检测的应用提供了一种可靠的分析方法.利用生物素化的CaF_2:Ce,Mn纳米荧光探针,我们还实现了对生物素受体过表达癌细胞的靶向荧光成像.通过概念性验证并利用手机连拍功能,我们证明了Mn^(2+)的长寿命发光可用于时间分辨荧光生物成像.这些研究结果为过渡金属长寿命发光在时间分辨荧光生物分析领域的应用提供了普适方法,也为过渡金属离子的新型、多功能用途开辟了新的方向.
基金
supported by National Program on Key Basic Research Project (973 Program, 2014CB845605)
the Strategic Priority Research Program of the CAS (XDB20000000)
the National Natural Science Foundation of China (21325104, 11774345, 21771185, 21501180 and 21650110462)
the CAS/SAFEA International Partnership Program for Creative Re-search Teams, the Youth Innovation Promotion Association (2016277)
the Chunmiao Project of Haixi Institutes of the CAS (CMZX-2016-002)
Natural Science Foundation of Fujian Province (2017I0018 and 2017J05095)
