Prof. SONG Yanlin and Prof. SU Meng's group at the Institute of Chemistry, Chinese Academy of Sciences (ICCAS), developed a printing platform to fabricate PC(Photonic crystals) biochips for POCT(Point-of-care testing), with a production capacity of up to 2,700 chips per hour using a single printer.

Point-of-care testing (POCT) with advantages such as high sensitivity, high selectivity, rapid response, easy integration, and low cost, has attracted increasing attention in biological detection. Many optical, electrical, electrochemical sensors are designed and demonstrated to recognize biomarkers even on single chip.

Among POCT methods, the fluoroimmunoassay is particularly valuable in clinical diagnostics and biotechnology applications, benefiting from the specificity, versatility and adaptability. However, the potentially weaker fluorescent signal at a low concentration of the analyte and optical interference from the background have a negative effect on the accuracy and sensitivity of fluoroimmunoassay.

Photonic crystals (PCs) —classical artificial optical metamaterials, are periodic dielectric materials that can modulate light at the microscale and nanoscale. With the characteristics of photonic bandgap and photonic localization effect, PCs can significantly enhance the fluorescence signals of biological labels in fluoroimmunoassay, greatly amplifying the sensitivity and resolution of biological detection. Making PCs a key technology in next-generation POCT devices.

By using PCs made of latex nanospheres with different sizes, fluorescence signals at various wavelengths can be significantly enhanced, greatly improving detection sensitivity. These nanospheres can be coated with specific capture antibodies to accurately target biomarkers.

Detection is carried out with a fluorescently labeled antibody and a simple portable device. This PC-based platform allows quick and simultaneous detection of multiple biomarkers, offering a versatile and highly promising tool for accurate, portable clinical diagnostics.

The printed biochips are inexpensive, and the biomarkers can be detected in small volumes of biofluids using a simple POCT device. This approach can be used to produce diagnostic tools for public health applications in remote areas.

Printed PC biochips for rapid and sensitive detection of biomarkers (Image by Springer Nature)

This study was published in Nature Protocols on July 24. 

Contact:

Prof. Yanlin Song

Institute of Chemistry, Chinese Academy of Sciences

Email: ylsong@iccas.ac.cn