Bionic optic nerve based on perovskite (CsPbBr 3) quantum-dots / 生物医学工程学杂志

The bionic optic nerve can mimic human visual physiology and is a future treatment for visual disorders. Photosynaptic devices could respond to light stimuli and mimic normal optic nerve function. By modifying (Poly(3,4-ethylenedioxythio-phene):poly (styrenesulfonate)) active layers with all-inorganic perovskite quantum dots, with an aqueous solution as the dielectric layer in this paper, we developed a photosynaptic device based on an organic electrochemical transistor (OECT). The optical switching response time of OECT was 3.7 s. To improve the optical response of the device, a 365 nm, 300 mW·cm -2 UV light source was used. Basic synaptic behaviors such as postsynaptic currents (0.225 mA) at a light pulse duration of 4 s and double pulse facilitation at a light pulse duration of 1 s and pulse interval of 1 s were simulated. By changing the way light stimulates, for example, by adjusting the intensity of the light pulses from 180 to 540 mW·cm -2, the duration from 1 to 20 s, and the number of light pulses from 1 to 20, the postsynaptic currents were increased by 0.350 mA, 0.420 mA, and 0.466 mA, respectively. As such, we realized the effective shift from short-term synaptic plasticity (100 s recovery of initial value) to long-term synaptic plasticity (84.3% of 250 s decay maximum). This optical synapse has a high potential for simulating the human optic nerve.

P3HT-based organic field effect transistor for low-cost, label-free detection of immunoglobulin G.

Currently, organic field effect transistors (OFETs) are widely used in the field of biodetection because of their inherent gain amplification function and good biocompatibility. However, the vast majority of OFET biosensors have disadvantages including a long preparation cycle, complicated processing and expensive materials. Thus, this paper proposes a simple and inexpensive preparation method for label-free detection of immunoglobulin G (IgG). In this work an active dielectric bilayer field effect transistor with 3D-printed silver source and drain electrodes was used. The active layer was modified by physically adsorbing an anti-IgG antibody on P3HT as a recognition element and then sealed with bovine serum albumin (BSA) to prevent nonspecific adsorption. The carrier mobility of the bilayer dielectric layer active field effect transistor reached 4.6 × 10-2 cm2/Vs, and the dynamic detection range for IgG spanned 6 orders of magnitude with a detection limit of 2.9 Picomolar (pM). Controlled experiments demonstrated that the developed sensor has high selectivity for IgG. Overall, this easy-to-operate and low-cost OFET biosensor has broad commercialization prospects and lays the foundation for the early clinical detection of disease-causing biomolecules.

Highly sensitive wearable strain sensor based on silver nanowires and nanoparticles.

Here, we propose a highly sensitive and stretchable strain sensor based on silver nanoparticles and nanowires (Ag NPs and NWs), advancing the rapid development of electronic skin. To improve the sensitivity of strain sensors based on silver nanowires (Ag NWs), Ag NPs and NWs were added to polydimethylsiloxane (PDMS) as an aid filler. Silver nanoparticles (Ag NPs) increase the conductive paths for electrons, leading to the low resistance of the resulting sensor (14.9 Ω). The strain sensor based on Ag NPs and NWs showed strong piezoresistivity with a tunable gauge factor (GF) at 3766, and a change in resistance as the strain linearly increased from 0% to 28.1%. The high GF demonstrates the irreplaceable role of Ag NPs in the sensor. Moreover, the applicability of our high-performance strain sensor has been demonstrated by its ability to sense movements caused by human talking, finger bending, wrist raising and walking.