Integrated CMOS On-Chip Bio-Sensing and Microscopy Platform for Miniaturized, Portable Fluorescence Detection and Imaging

Background

Fluorescence-based bio-sensing and microscopy are foundational tools in biomedical research, diagnostics, and life sciences. These techniques enable the detection and visualization of specific biomolecules or cellular structures by labeling them with fluorescent markers, which emit light upon excitation. Traditional fluorescence microscopes and sensors are indispensable for applications such as disease diagnostics, drug discovery, and cellular imaging. However, these instruments are typically large, expensive, and require skilled operators, making them impractical for point-of-care (POC) diagnostics, fieldwork, or resource-limited settings. The growing demand for rapid, accessible, and cost-effective diagnostic solutions has driven significant interest in miniaturizing fluorescence detection systems while maintaining high sensitivity and specificity.

Despite advances in miniaturization, current approaches to on-chip fluorescence sensing and imaging face several critical limitations. Conventional optical filters and lenses used to isolate weak fluorescence signals from strong excitation light are challenging to integrate onto semiconductor chips using standard manufacturing processes. Off-chip optical components add bulk, cost, and alignment complexity, undermining portability and scalability. Furthermore, on-chip filters fabricated with traditional materials often exhibit poor rejection of excitation light, limited spectral selectivity, and sensitivity to incident angle, resulting in high background noise and reduced signal fidelity. Existing CMOS-based sensors also struggle with low sensitivity and high noise when detecting weak fluorescence, and their imaging resolution is typically constrained by the inability to integrate effective light-guiding or focusing elements at the chip level. These challenges collectively hinder the deployment of robust, high-performance, and truly portable fluorescence bio-sensing and microscopy platforms suitable for widespread clinical and field use.

Technology

The described technology is a fully integrated CMOS-based on-chip fluorescence bio-sensor and microscopy platform designed to miniaturize and replace traditional, bulky fluorescence detection and imaging systems. It features high-sensitivity photo-sensing circuits capable of detecting weak fluorescence signals, and a suite of advanced on-chip optical filters—including sub-wavelength copper plasmonic waveguide arrays, 2D grating anomaly filters, and metamaterial filters—that selectively block excitation light while transmitting fluorescence emission. For imaging, the platform incorporates either arrays of copper hollow waveguides to channel fluorescence directly to individual pixels or reflective Fresnel lenses to focus and magnify images. All components are fabricated using standard CMOS processes, allowing bio-samples to be prepared directly on the chip, illuminated by an external light source, and analyzed in real time. The system is modular, supporting both single-chip and double-chip architectures, and can interface with personal electronic devices such as smartphones for portable, point-of-care diagnostics.

This solution is differentiated by its unique integration of multiple optical filtering technologies and imaging components directly onto CMOS chips using standard semiconductor fabrication methods. The copper plasmonic waveguide filters exploit copper’s wavelength-dependent optical properties for robust, angle-tolerant rejection of excitation light, while the 2D grating anomaly and metamaterial filters provide tunable and complementary spectral filtering for various fluorophores and illumination conditions. The monolithic integration of differential photodiodes, low-noise readout circuits, and on-chip optical elements enables highly sensitive, low-noise detection and high-resolution imaging without the need for bulky optics or external filtering hardware. The platform’s compatibility with mass-manufacturing and its ability to deliver real-time, high-performance fluorescence bio-sensing and microscopy in a compact, cost-effective, and portable form factor make it particularly well-suited for point-of-care biomedical diagnostics and other field-deployable applications.

Benefits

• Compact and portable fluorescence bio-sensing and microscopy platform suitable for point-of-care diagnostics.
• Cost-effective mass manufacturing using standard CMOS fabrication processes without costly post-processing.
• High-sensitivity detection of weak fluorescence signals with low noise and high dynamic range via integrated differential photodiodes and advanced readout circuits.
• Effective on-chip optical filtering using novel copper plasmonic waveguides, 2D grating anomaly filters, and metamaterial resonators to robustly reject excitation light and enhance signal-to-noise ratio.
• Integrated on-chip optical lenses and hollow waveguides for fluorescence collection, imaging, and magnification enabling high-resolution fluorescence microscopy on a chip.
• Modular system architectures supporting both single-chip imaging and double-chip microscopy with magnification comparable to traditional bulky microscopes.
• Compatibility with personal electronic devices (e.g., smartphones) for real-time data processing and diagnostic reporting.

Applications

• Point-of-care medical diagnostics
• Portable fluorescence microscopy
• On-chip bio-sample analysis
• Smartphone-based diagnostic devices
• Environmental pathogen detection

Additional info

This integrated CMOS platform performs on-chip fluorescence bio-sensing and microscopy. It employs high-sensitivity photo-sensing circuits and on-chip optical filters (plasmonic, grating, metamaterial) to selectively block excitation light. Integrated optical components, such as hollow waveguides or reflective Fresnel lenses, facilitate imaging and magnification. Fabricated using standard CMOS processes, this system enables direct, compact bio-sample analysis.