2026-09-21T08:31:31Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/130098 2026-02-10 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

application/pdf en text Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-08-01 The student, Weinan Liu, accepted the attached license on 2025-07-17 at 19:10. The student, Weinan Liu, submitted this Dissertation for approval on 2025-07-17 at 19:13. This Dissertation was approved for publication on 2025-07-18 at 14:55. DSpace SAF Submission Ingestion Package generated from Vireo submission #22563 on 2025-10-25 at 15:31:00 Photonic resonator absorption microscopy for dynamic point of care biosensing Liu, Weinan 2025-07-18 Cunningham, Brian T. Cunningham, Brian T. Do, Minh N. Gruev, Viktor Zhao, Yang Digital-resolution Biosensing Photonic Crystal Point-of-care Microscopy Metasurface Computational Imaging Biomedical Detection eng This dissertation introduces Photonic Resonator Absorption Microscopy (PRAM), a label-free, digital-resolution biosensing platform designed for highly sensitive and accessible point-of-care diagnostics. By coupling photonic crystal (PC) surfaces with gold nanoparticle (AuNP) tags, PRAM enables attomolar detection of biomolecules without enzymatic amplification or complex workflows. To advance PRAM for real-world applications, several innovations are presented. A portable, automated PRAM system (ap-PRAM) integrates motorized autofocus, large field-of-view (FOV) tiling, and a differential dynamic detection algorithm to enable real-time, single-particle kinetic analysis of binding and unbinding events. These capabilities are demonstrated in both sandwich immunoassays for viral antibodies (HIV, HCV) and a target recycling amplification assay for miRNA, achieving detection limits as low as 1 aM. In parallel, a miniaturized PRAM system (PRAM Mini) is developed, featuring compact optics, smartphone integration, and digital image processing for decentralized or resource-limited settings. To further enhance signal spatial uniformity and polarization independence, a two-dimensional PC substrate is designed and fabricated, improving signal consistency across the sensor surface. Together, these developments establish PRAM as a versatile and scalable platform with broad potential for clinical diagnostics, liquid biopsy, and dynamic biosensing in both laboratory and point-of-care environments. 2025-08 Text https://hdl.handle.net/2142/130098 Copyright 2025 Weinan Liu Electrical & Computer Eng Electrical & Computer Engr University of Illinois Urbana-Champaign Ph.D. Dissertation