Bottom side partially etched D-shaped PCF biosensor for early diagnosis of cancer cellsShivam Singh, Bhargavi Chaudhary, Anurag Upadhyay and Sofyan A. TayaEur. Phys. J. Plus, 138 6 (2023) 511DOI: https://doi.org/10.1140/epjp/s13360-023-04133-8