We investigate a novel, to the best of our knowledge, D-type photonic crystal fiber-based refractive index microbiosensor that works on surface plasmon resonance. We study the performance of the proposed sensor using the finite element method. Further, we analyze the influence of various materials, namely, gold, silver, and indium tin oxide that are deposited on the D-type fiber surface. Of these metals, gold has been examined to be advantageous owing to its enhanced sensitivity and greater chemical stability. The proposed microbiosensor exhibits a high wavelength sensitivity of 19,000 nm/RIU in the sensing range of 1.40–1.41, and its wavelength interrogation resolution is 5.26 × 10−6 RIU. Besides, this novel scheme provides a high amplitude sensitivity of 569 RIU−1 with the corresponding resolution of 2.63 × 10−6 RIU. Further, the linearity of the proposed microbiosensor, R2, is 0.9745 in the sensing environment of the refractive index ranging between 1.31 and 1.40. Finally, optimizing the metal coating thickness, diameter of the air-hole, and the lattice pitch of the proposed sensor have been conducted systematically, in order to augment the sensing performance of the proposed sensor. We foresee that the proposed microbiosensor would turn out to be an appropriate candidate in sensing the analytes of high refractive index. © 2021 Optical Society of America