Mahajan Prasad G, Kolekar G B, Patil Shivajirao R
Fluorescence Spectroscopy Laboratory, Department of Chemistry, Shivaji University Kolhapur, Maharashtra, India.
Luminescence. 2017 Aug;32(5):845-854. doi: 10.1002/bio.3262. Epub 2017 Jan 5.
Polyvinyl pyrrolidone (PVP) crowned chrysene nanoparticles (CHYNPs) were prepared by using a reprecipitation method. Dynamic light scattering (DLS) and scanning electron microscope (SEM) studies indicate that the monodispersed spherical nanoparticles bear a negative charge on their surfaces. The bathochromic spectral shift in the UV-visible and fluorescence spectrum of CHYNPs from chrysene (CHY) in acetone solution supports the J- type aggregation of nanoparticles. The aggregation-induced enhanced emission of CHYNPs at 486 and 522 nm decreases by increasing the concentration of the Ca ion solution. It can display an ON-OFF type fluorescence response with high selectivity towards Ca ions aqueous medium. Furthermore, the in situ generated PVP-CHYNPs-Ca ensemble could recover the quenched fluorescence upon the addition of fluoride anions resulting in an OFF-ON type sensor. The present method has a correlation coefficient R = 0.988 with a detection limit of 1.22 μg/mL for Ca in the aqueous medium. The fluorescence changes of PVP crowned CHYNPs upon the addition of Ca and F can be utilized as an INHIBIT logic gate at the molecular level, using Ca and F chemical inputs and the fluorescence intensity signal as output.
采用复沉淀法制备了聚乙烯吡咯烷酮（PVP）包覆的芘纳米颗粒（CHYNPs）。动态光散射（DLS）和扫描电子显微镜（SEM）研究表明，单分散的球形纳米颗粒表面带负电荷。芘纳米颗粒在丙酮溶液中的紫外可见光谱和荧光光谱中的红移支持了纳米颗粒的J型聚集。随着钙离子溶液浓度的增加，芘纳米颗粒在486和522nm处的聚集诱导增强发射减弱。它能在水介质中对钙离子表现出高选择性的开-关型荧光响应。此外，原位生成的PVP-CHYNPs-Ca体系在加入氟离子后可恢复猝灭的荧光，从而形成一个关-开型传感器。本方法在水介质中对钙离子的相关系数R = 0.988，检测限为1.22μg/mL。加入钙和氟后，PVP包覆的芘纳米颗粒的荧光变化可作为分子水平上的抑制逻辑门，以钙和氟的化学输入以及荧光强度信号作为输出。
