Fluoroimmunoassay of influenza virus using sulfur-doped graphitic carbon nitride quantum dots coupled with AgS nanocrystals.

Novel sulfur-doped graphitic carbon nitride quantum dots (S-gCNQDs) are synthesized using a single-source precursor in a one-step solvothermal process. The S-gCNQDs with a size of ~ 5-nm displayed a strong green intrinsic fluorescence at 512 nm when excited at 400 nm, with a quantum yield of ~ 33% in aqueous solution. The prepared S-gCNQDs and AgS nanocrystals were applied as innovative functional materials to fabricate a biosensor for virus detection based on the conjugation of specific anti-human influenza A monoclonal antibody to the S-gCNQDs and AgS NCs, respectively.

Label-Free Biomedical Imaging Using High-Speed Lock-In Pixel Sensor for Stimulated Raman Scattering.

Raman imaging eliminates the need for staining procedures, providing label-free imaging to study biological samples. Recent developments in stimulated Raman scattering (SRS) have achieved fast acquisition speed and hyperspectral imaging. However, there has been a problem of lack of detectors suitable for MHz modulation rate parallel detection, detecting multiple small SRS signals while eliminating extremely strong offset due to direct laser light.

A Stimulated Raman Scattering CMOS Pixel Using a High-Speed Charge Modulator and Lock-in Amplifier.

A complementary metal-oxide semiconductor (CMOS) lock-in pixel to observe stimulated Raman scattering (SRS) using a high speed lateral electric field modulator (LEFM) for photo-generated charges and in-pixel readout circuits is presented. An effective SRS signal generated after the SRS process is very small and needs to be extracted from an extremely large offset due to a probing laser signal. In order to suppress the offset components while amplifying high-frequency modulated small SRS signal components, the lock-in pixel uses a high-speed LEFM for demodulating the SRS signal, resistor-capacitor low-pass filter (RC-LPF) and switched-capacitor (SC) integrator with a fully CMOS differential amplifier.

Ultra-low-voltage CMOS-based current bleeding mixer with high LO-RF isolation.

This journal presents an ultra-low-voltage current bleeding mixer with high LO-RF port-to-port isolation, implemented on 0.13 μm standard CMOS technology for ZigBee application. The architecture compliments a modified current bleeding topology, consisting of NMOS-based current bleeding transistor, PMOS-based switching stage, and integrated inductors achieving low-voltage operation and high LO-RF isolation.

Low power upconversion mixer for medical remote sensing.

This work presents the design of a low power upconversion mixer adapted in medical remote sensing such as wireless endoscopy application. The proposed upconversion mixer operates in ISM band of 433 MHz. With the carrier power of -5 dBm, the proposed mixer has an output inferred 1 dB compression point of -0.