@article{li_jin_jiang_an_ji_huang_2024, title={Influence of reaction cell electrodes on organic electrochemical transistors}, volume={124}, ISSN={["1077-3118"]}, DOI={10.1063/5.0176349}, abstractNote={Organic electrochemical transistors (OECTs) hold great potential in various applications, including biosensing and neural network computation. Traditional “all-in-one” OECT device architecture faces the problems of unclear amplification mechanisms and complex side reactions, to name a few. The reaction cell OECT (RC-OECT) device architecture, proposed by Ting et al. [Adv. Funct. Mater. 31(19), 2010868 (2021)], effectively resolves these problems. Furthermore, in many applications of OECTs, such as high throughput (bio)sensing, an OECT device array instead of a single OECT is needed. Therefore, the size (area) of the OECT device, which represents the amount of occupied chip real estate and the integration of the device, matters. In this paper, we developed a hydrogen peroxide sensor based on the RC-OECT. We utilized an RC cathode modified by the poly(3,4-ethylenedioxythiophene) polystyrene sulfonate film and a Ag/AgCl OECT gate electrode for facilitating device integration, varied RC anode area, and achieved optimization of at least one of the two parameters, sensitivity and lower limit of detection (LLoD), in conjunction with the level of integration of the device. Multiple quantitative sensitivity metrics have been adopted in this work. We also evaluated the correlation between RC anode area and LLoD. In addition, a mechanistic analysis of the RC-OECT device structure, in terms of faradic and non-faradaic currents, was carried out to illustrate the interplay between sensing performance and the electrode area of the reaction cell. This mechanistic analysis provides insights for miniaturizing OECT devices with the RC-OECT architecture.}, number={9}, journal={APPLIED PHYSICS LETTERS}, author={Li, Huiyuan and Jin, Zichen and Jiang, Xiaoning and An, Meiwen and Ji, Jianlong and Huang, Di}, year={2024}, month={Feb} }
 @article{ji_wang_zhang_wang_niu_jiang_qiao_ren_zhang_sang_et al._2023, title={Pulse electrochemical synaptic transistor for supersensitive and ultrafast biosensors}, ISSN={["2567-3165"]}, DOI={10.1002/inf2.12478}, abstractNote={High sensitivity and fast response are the figures of merit for benchmarking commercial sensors. Due to the advantages of intrinsic signal amplification, bionic ability, and mechanical flexibility, electrochemical transistors (ECTs) have recently gained increasing popularity in constructing various sensors. In the current work, we have proposed a pulse‐driven synaptic ECT for supersensitive and ultrafast biosensors. By pulsing the presynaptic input (drain bias, VD) and setting the modulation potential (gate bias) near transconductance intersection (VG,i), the synaptic ECT‐based pH sensor can achieve a record high sensitivity up to 124 mV pH−1 (almost twice the Nernstian limit, 59.2 mV pH−1) and an ultrafast response time as low as 8.75 ms (7169 times faster than the potentiostatic sensors, 62.73 s). The proposed synaptic sensing strategy can effectively eliminate the transconductance fluctuation issue during the calibration process of the pH sensor and significantly reduce power consumption. Besides, the most sensitive working point at VG,i has been elaborately figured out through a series of detailed mathematical derivations, which is of great significance to provide higher sensitivity with quasi‐nonfluctuating amplification capability. The proposed electrochemical synaptic transistor paired with an optimized operating gate offers a new paradigm for standardizing and commercializing high‐performance biosensors.image}, journal={INFOMAT}, author={Ji, Jianlong and Wang, Zhenxing and Zhang, Fan and Wang, Bin and Niu, Yan and Jiang, Xiaoning and Qiao, Zeng-ying and Ren, Tian-ling and Zhang, Wendong and Sang, Shengbo and et al.}, year={2023}, month={Aug} }
 @article{ji_wang_liu_jiang_zhang_peng_sang_sun_wang_2021, title={Dual-liquid-gated electrochemical transistor and its neuromorphic behaviors}, volume={87}, ISSN={["2211-3282"]}, DOI={10.1016/j.nanoen.2021.106116}, abstractNote={Organic electrochemical transistors (OECTs) are attracting great interest in the field of bioelectronics due to their low operating voltage, flexibility, and biocompatibility. Tunability of the static and transient characteristics renders OECTs with flexible electrical responses and versatile functionalities. However, existing tuning methods are known by changing the structure or composition of OECTs, which are empirical due to the lack of accurate structure-function relationships. Here, we report a post-fabrication and facile tuning method by using a dual-liquid-gate configuration. Based on this, critical parameters of OECT, e.g., threshold voltage (VTH), gate bias for the peak transconductance (VG(g*m)), electric hysteresis (Vhys), minimum of the subthreshold swing (SS*), and response time (τ), can be readily tuned over a range of 0.52 V, 0.48 V, 0.20 V, 0.38 V/decade and 7.2 ms, respectively. We have also developed corresponding mathematical analyses based on the dual-liquid-gating process. Detailed studies on the transient electrical properties demonstrate that auxiliary-gate biases influence the electrochemical doping/de-doping state of the semiconducting channel during the main-gate bias sweeping. Furthermore, typical neuromorphic behaviors of paired-pulse depression and decay time were successfully controlled by varying the auxiliary-gate bias. The proposed dual-liquid-gating is ready for precise engineering on OECT, which is beneficial as an effective tool for conducting an in-depth theoretical study on OECT, constructing multifunctional sensors, and developing more plasticizable neuromorphic devices.}, journal={NANO ENERGY}, author={Ji, Jianlong and Wang, Hongwang and Liu, Ran and Jiang, Xiaoning and Zhang, Qiang and Peng, Yubo and Sang, Shengbo and Sun, Qijun and Wang, Zhong Lin}, year={2021}, month={Sep} }
 @article{ji_wang_wang_zhang_duan_sang_huang_li_zhang_jiang_2021, title={Dynamic-coupling analyses of cells localization by the negative dielectrophoresis}, volume={235}, ISSN={["2041-2983"]}, DOI={10.1177/0954406220929050}, abstractNote={Negative dielectrophoresis is widely used in cell localization for long-term observations such as the impedance analysis, in vivo drug screening, and cell patterns. However, the coupling effect of AC electrokinetics, including negative dielectrophoresis, AC electroosmosis, and electrothermal flow is still unclear. This work investigated cell localization based on the dynamic-coupling of dielectrophoresis, AC electroosmosis, and electrothermal flow. A two-dimensional finite element model that consisted of interdigitated array electrodes was established. The effects of system parameters on the capture efficiency were investigated, when the medium conductivity was in the range of 0.001–1 S/m. The selection of the medium conductivity is suggested to be the first step of the experiment design. Then, the choice of AC frequency and AC amplitude requires balancing the effects of transmembrane potential and temperature rise on cell viability. Besides, particular electrode spacing is evidenced to be only efficient for a specific cell diameter. Thus, the electrode spacing of the microfluidic chip needs to be optimized according to the cell's diameter.}, number={2}, journal={PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE}, author={Ji, Jianlong and Wang, Jingxiao and Wang, Liu and Zhang, Qiang and Duan, Qianqian and Sang, Shengbo and Huang, Qing and Li, Shanshan and Zhang, Wendong and Jiang, Xiaoning}, year={2021}, month={Jan}, pages={402–411} }
 @article{ji_zhang_wang_huang_jiang_zhang_sang_guo_li_2020, title={Three-dimensional analyses of cells' positioning on the quadrupole-electrode microfluid chip considering the coupling effect of nDEP, ACEO, and ETF}, volume={165}, ISSN={["1873-4235"]}, DOI={10.1016/j.bios.2020.112398}, abstractNote={Microfluidic chips integrated with negative dielectrophoresis (nDEP) and electrochemical impedance spectroscopy have wide applications in cell sensing. Accurate analysis of the kinematics and dynamics of cells in the nDEP process is crucial to improve the positioning accuracy and electric cell-substrate impedance sensing (ECIS) performance. This paper reports employing the three-dimensional (3D) finite element model to analyze the coupling effects of electrokinetic flows (EF) such as alternating current electroosmosis (ACEO) and the electrothermal flow (ETF) on the nDEP positionings. On the quadrupole ECIS microfluid chip, three typical nDEP results are observed in the frequency range of 100 Hz-25 MHz and the amplitude range of 1-20 Vp-p. Simulations Based on the 3D hybrid model provide abundant kinematic information and show clear dynamic processes. Based on the discussion, the mechanisms of nDEP localizations and phase-tuning manipulations are proposed. It is found that the drag force could affect the particle's movement through the vortex of the flow field induced by ACEO and ETF, while the nDEP forces dominate the particles' locations on the substrate. Thus, the 3D dynamic-coupling analyses could help design the quadrupole-electrode microfluid chip and optimize the manipulation parameters in the experiment.}, journal={BIOSENSORS & BIOELECTRONICS}, author={Ji, Jianlong and Zhang, Jingjing and Wang, Jingxiao and Huang, Qing and Jiang, Xiaoning and Zhang, Wendong and Sang, Shengbo and Guo, Xiaoliang and Li, Shanshan}, year={2020}, month={Oct} }
 @article{ji_li_chen_wang_jiang_zhuo_liu_yang_gu_sang_et al._2019, title={In situ fabrication of organic electrochemical transistors on a microfluidic chip}, volume={12}, ISSN={["1998-0000"]}, DOI={10.1007/s12274-019-2462-0}, number={8}, journal={NANO RESEARCH}, author={Ji, Jianlong and Li, Mangmang and Chen, Zhaowei and Wang, Hongwang and Jiang, Xiaoning and Zhuo, Kai and Liu, Ying and Yang, Xing and Gu, Zhen and Sang, Shengbo and et al.}, year={2019}, month={Aug}, pages={1943–1951} }
 @article{ge_ji_zhang_yuan_wang_zhang_sang_2019, title={Unraveling the intrinsic magnetic property of triangular zigzag edge bilayer graphene nanoflakes: A first-principles theoretical study}, volume={730}, ISSN={["1873-4448"]}, DOI={10.1016/j.cplett.2019.06.033}, abstractNote={It has been known for a long time that graphene flakes of certain geometries can develop spontaneous spin polarization. Here, it is studied what happens when two triangular graphene nanoflakes, possibly different sizes, are placed in close proximity with AB (Bernal) stacking. The results of first-principles calculations show that the magnetic ground state of the bilayer system depends on the different sizes of the two nanoflakes, and spin-related energy gap can be controlled with external electric fields. Under certain circumstances, the system even can be tuned into half-metallic nature, which might potentially be exploited in future spintronics applications.}, journal={CHEMICAL PHYSICS LETTERS}, author={Ge, Yang and Ji, Jianlong and Zhang, Qiang and Yuan, Zhongyun and Wang, Renxin and Zhang, Wendong and Sang, Shengbo}, year={2019}, month={Sep}, pages={326–331} }
 @article{ge_ji_zhang_yuan_jian_yang_xiao_zhang_sang_2019, title={Zero-energy-state-oriented tunability of spin polarization in zigzag-edged bowtie-shaped graphene nanoflakes under an electric field}, volume={30}, ISSN={["1361-6528"]}, DOI={10.1088/1361-6528/aaf549}, abstractNote={A comprehensive first-principles study of the correlation between zero-energy states and the tunability of the spin-selective semiconducting properties of zigzag-edged bowtie-shaped graphene nanoflakes under an electric field is presented for the first time. We demonstrate that the spin degenerate semiconducting ground state can be lifted by the electric field. In particular, we find that the number of zero-energy states (’the nullity’) defined by the structural configuration determines the complexity and efficiency of the tunability of spin polarization. The fine-tuning of spin-dependent properties by the electric field originates from the manipulation of spin-polarized molecular orbital energies. We expect this study to aid the design of more effective and controllable low-dimensional molecular spintronics.}, number={8}, journal={NANOTECHNOLOGY}, author={Ge, Yang and Ji, Jianlong and Zhang, Qiang and Yuan, Zhongyun and Jian, Aoqun and Yang, Xing and Xiao, Gaokeng and Zhang, Wendong and Sang, Shengbo}, year={2019}, month={Feb} }