公开(公告)号：US20210310949A1

公开(公告)日：2021-10-07

申请号：US17219108

申请日：2021-03-31

Applicant: INDIAN INSTITUTE OF SCIENCE EDUCATION AND RESEARCH

Inventor： Kamal Priya SINGH ,  Mehra Singh SIDHU ,  Biswajit PANDA

IPC: G01N21/64 ,  C09K11/06 ,  C07K14/435

Abstract: Disclosed herein is a novel phenomenon to create a nano-confined, dopant-free, electron spin-dependent fluorescence (SDF) in spider silk by fundamentally transforming its local molecular structure with femtosecond-pulses (206), having fluence below an ablation threshold. Electron-spin dependence of the fluorescent patterns created on the silk sample are confirmed by measuring the fluorescence intensity at different microwave frequencies. The fluorescent intensity exhibits microwave magnetic resonances at 2.88 GHz and 1.44 GHz at room-temperature. The SDF in laser-transformed silk can thereby enable a new-class of tough yet elastic silk-based quantum sensor and hybrid nano-mechanical ultrasensitive cantilevers on a micro-chip. X-ray diffraction (XRD), Raman-spectroscopy, direct atomistic imaging with high-resolution transmission electron microscopy (HR-TEM) and model-building studies are carried out to exhibit the change in the molecular structure and unveil creation of crown-ring like structure in nanocrystals of fluorescent silk with localized electrons possessing mid-gap states.