A 640×640 ISFET array for detecting cell metabolism

Ion sensitive field effect transistor(ISFET)devices are highly accurate,convenient,fast and low-cost in the detection of ions and biological macromolecules,such as DNA molecules,antibodies,enzymatic substrates and cellular metabolites.For high-throughput cell metabolism detection,we successfully designed a very large-scale biomedical sensing application specific integrated circuit(ASIC)with a 640×640 ISFET array.The circuit design is highly integrated by compressing the size of a pixel to 7.4×7.4μm^(2)and arranging the layout of even and odd columns in an interdigital pattern to maximize the utilization of space.The chip can operate at a speed of 2.083M pixels/s and the dynamic process of the fluid flow on the surface of the array was monitored through ion imaging.The pH sensitivity is 33±4 mV/pH and the drift rate is 0.06 mV/min after 5 h,indicating the stability and robustness of the chip.Moreover,the chip was applied to monitor pH changes in CaSki cells metabolism,with pH shifting from 8.04 to 7.40 on average.This platform has the potential for continuous and parallel monitoring of cell metabolism in single-cell culture arrays.

The next-generation sequencing technology and application

As one of the key technologies in biomedical research,DNA sequencing has not only improved its productivity with an exponential growth rate but also been applied to new areas of application over the past few years.This is largely due to the advent of newer generations of sequencing platforms,offering ever-faster and cheaper ways to analyze sequences.In our previous review,we looked into technical characteristics of the nextgeneration sequencers and provided prospective insights into their future development.In this article,we present a brief overview of the advantages and shortcomings of key commercially available platforms with a focus on their suitability for a broad range of applications.

Low-cost hybrid integrated 4 × 25 GBaud PAM-4CWDM ROSA with a PLC-based arrayed waveguide grating de-multiplexer

We demonstrate a low-cost hybrid integrated and compact 100 GBaud four-lane coarse wavelength division multiplexing (CWDM) receiver optical sub-assembly (ROSA) based on an arrayed waveguide grating de-multiplexer in the O band. To achieve the horizontal light coupling between the planar light-wave circuit (PLC) based arrayed waveguide grating de-multiplexer and photodetector array, a 42°polished facet is applied for total reflection.A flexible printed circuit with high-frequency coplanar waveguides is used for a power supply of trans-impedance amplifier and signal transmission.The fabricated CWDM ROSA module, whose size is 18mm×22mm×6mm, shows a 3 dB bandwidth of 21.2,18.4,19.6,and 19.3 GHz,respectively,in each lane. The overall symbol error rates are at a magnitude of 10^-7 for 25 GBaud four-level pulse amplitude modulation (PAM-4) transmission with an average input optical power of 5dBm.

Solution processed low power organic field-effect transistor bio-chemical sensor of high transconductance efficiency

Developing organic field-effect transistor(OFET)biosensors for customizable detection of biomarkers for many diseases would provide a low-cost and convenient tool for both biological studies and clinical diagnosis.In this work,design principles of the OFET transducer for biosensors were derived to relate the signal-to-noise ratio(SNR)to the device-performance parameters.Steep subthreshold swing(SS),proper threshold voltage(Vth),good-enough bias-stress stability,and mechanical durability are shown to be the key prerequisites for realizing OFET bio-sensors of high transconductance efficiency(gm/ID)for large SNR.Combining a low trap-density channel and a high-k/low-k gate dielectric layer,low-temperature(<100℃)solution-processed flexible OFETs can meet the performance requirements to maximize the gm/ID.An extended gate-structure OFET biosensor was further implemented for label-free detection of miR-21,achieving a detection limit below 10 pM with high selectivity at a low operation voltage(<1 V).

Improved extinction ratio of Mach-Zehnder based optical modulators on CMOS platform

Silicon based optical modulators with improved extinction ratio （ER） of 25 dB were demon- strated on complementary metal oxide semiconductor （CMOS） platform. It was proposed that the effect of optical absorption due to free carriers accumulated in silicon should be considered in the analysis of device configuration. Experimental results presented in this study were identical with the proposed analyses. The modulators were operated with the data transmission rate of 3.2 Gbps.