Photoelectrochemical detection of copper ions based on a covalent organic framework with tunable properties.

Copper ions (Cu2+) play an essential role in various cellular functions, including respiration, nerve conduction, tissue maturation, oxidative stress defense, and iron metabolism. Covalent organic frameworks (COFs) are a class of porous crystalline materials with directed structural designability and high stability due to the combination of different monomers through covalent bonds. In this study, we synthesized a porphyrin-tetrathiazole COF (TT-COF(Zn)) with Zn-porphyrin and tetrathiafulvalene (TTF) as monomers and used it as a photoactive material. The strong light absorption of metalloporphyrin and the electron-rich properties of supplied TTF contribute to its photoelectrochemical performance. Additionally, the sulfur (S) in the TTF can coordinate with Cu2+. Based on these properties, we constructed a highly sensitive photoelectrochemical sensor for detecting Cu2+. The sensor exhibited a linear range from 0.5 nM to 500 nM (R2 = 0.9983) and a detection limit of 0.15 nM for Cu2+. Notably, the sensor performed well when detecting Cu2+ in water samples.

Dual Functional Conjugated Acetylenic Polymers: High-Efficacy Modulation for Organic Photoelectrochemical Transistors and Structural Evolution for Bioelectronic Detection.

Conjugated acetylenic polymers (CAPs) have emerged as a unique class of metal-free semiconductors with tunable electrical and optical properties yet their full potential remains largely unexplored. Organic bioelectronics is envisioned to create more opportunities for innovative biomedical applications. Herein, we report a poly(1,4-diethynylbenzene) (pDEB)/NiO gated enhancement-mode poly(ethylene dioxythiophene)-poly(styrene sulfonate) organic photoelectrochemical transistor (OPECT) and its structural evolution toward bioelectronic detection. pDEB was synthesized via copper-mediated Glaser polycondensation of DEB monomers on the NiO/FTO substrate, and the as-synthesized pDEB/NiO/FTO can efficiently modulate the enhancement-mode device with a high current gain. Linking with a sandwich immunoassay, the labeled alkaline phosphatase can catalyze sodium thiophosphate to generate H2S, which will react with the diacetylene group in pDEB through the Michael addition reaction, resulting in an altered molecular structure and thus the transistor response. Exemplified by HIgG as the model target, the developed biosensor achieves highly sensitive detection with a linear range of 70 fg mL-1-10 ng mL-1 and a low detection limit of 28.5 fg mL-1. This work features the dual functional CAP-gated OPECT, providing not only a novel gating module but also a structurally new rationale for bioelectronic detection.

Organic Molecular Probe Enabled Ionic Current Rectification toward Subcellular Detection of Glutathione with High Selectivity, Sensitivity, and Recyclability.

Single-cell interrogation with the solid-state nanoprobes enables understanding of the linkage between cellular behavior and heterogeneity. Herein, inspired by the charge property of the organic molecular probe (OMP), a generic ionic current rectification (ICR) single-cell methodology is established, exemplified by subcellular detection of glutathione (GSH) with high selectivity, sensitivity, and recyclability. The as-developed nanosensor can transduce the subcellular OMP-GSH interaction via a sensitive ionic response, which stems from the superior specificity of OMP and its essential charge property. In addition, the nanosensor exhibits good reversibility, since the subsequent tandem reaction after the recognition can well recover the sensing surface. Given the diverse structures and tailorable charge properties of OMP, this work underpins a new and general method of OMP-based ICR single-cell analysis.

Biological modulating organic photoelectrochemical transistor through in situ enzymatic engineering of photoactive gate for sensitive detection of serum alkaline phosphatase.

Innovative optoelectronics are expected to play more important role in clinical diagnosis. In this study, on the basis of sensitive gating effect by in situ enzymatic functionalization of semiconductors, a novel organic photoelectrochemical transistor (OPECT) detection of serum alkaline phosphatase (ALP) level was demonstrated. Specifically, the OPECT detection operates upon the ALP-catalyzed hydrolysis of sodium thiophosphate to yield hydrogen sulfide (H2S), which could in situ generate CdS on the TiO2 electrode in the presence of Cd2+ cations. Correlated to the ALP level, the CdS directly formed on and interfacing with the TiO2 could sensitively gating the poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) channel, allowing unique optoelectronic detection of serum ALP level with a linear range from 0.005 to 15 U L-1 and a detection limit corresponding to 0.0012 U L-1 (S/N = 3). This study offers not only an optoelectronic method for detection of serum ALP level, but also a perspective for unique OPECT gating and application. Moreover, the general catalytic abilities of enzymes to produce functional species and their rich interactions with various gate substrates further provide great space for futuristic OPECT detection in enzyme-associated diseases.

Duplex-Specific Nuclease-Enabled Target Recycling on Semiconducting Metal-Organic Framework Heterojunctions for Energy-Transfer-Based Organic Photoelectrochemical Transistor miRNA Biosensing.

Semiconductor metal-organic frameworks (MOFs) and heterojunctions have gained increasing attention in many fields, yet their full potential remains largely unexplored. Advanced optobioelectronics are envisioned to create more opportunities for innovative biomedical applications. This study reports a UiO-66-NH2 (U6N)/CdS quantum dots (QDs)-gated organic photoelectrochemical transistor (OPECT) and its application toward energy-transfer-based sensitive microRNA-166a (miRNA-166a) detection assisted by duplex-specific nuclease (DSN)-enabled target recycling. Specifically, a U6N/CdS QDs photoanode was fabricated and shown to be efficiently gating a poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT/PSS) channel, while the DSN-enabled release of Au-reporters and hybridization upon the U6N/CdS QDs photoanode could significantly inhibit the photoanode response via an energy transfer process and thus modulate the device response, permitting novel dual-amplified optobioelectronic miRNA-166a detection with a low detection limit of 1.0 fM. This work not only features the DSN-amplified miRNA detection via an OPECT route but also unveils the potential of semiconductor MOF heterojunctions for futuristic optobioelectronics.

Hybridization chain reaction for regulating surface capacitance of organic photoelectrochemical transistor toward sensitive miRNA detection.

Photon-enabled bioelectronics has long been pursued in modern electronics due to their non-contact, remote-control, and even self-powered function interfacing the biological world with semiconductor devices. The debuting organic photoelectrochemical transistor (OPECT) relies on the photovoltage generated by the semiconductors to modulate the channel conductance, which enables light-fueled operation at zero gate bias. Inspired by the insulating nature of macrobiomolecules and surface capacitance mechanism, herein we demonstrate the biological regulation of the surface capacitance towards new OPECT biodetection, which was exemplified by a CdS quantum dots/TiO2 nanotubes photoanode accommodating hybridization chain reaction (HCR) amplification with the target of biomarker miRNA-17. Formation of the non-conducting DNA layer from the miRNA-17-oriented HCR could decrease the surface capacitance and increase the corresponding fractional potential drop, shifting the transfer curve horizontally to higher gate voltage and thus producing different drain currents. The OPECT biosensor exhibited a linear relationship with the miRNA-17 concentration on the logarithmic axis in the range from 1 pm. to 10 µm with a detection limit of 1 pm. This work not only represented a generic methodology of miRNA detection, but also provided a universal mechanism for the operation of advanced OPECT bioanalytics.

The therapeutic effect of pelvic floor muscle exercise on urinary incontinence after radical prostatectomy: a meta-analysis.

Pelvic floor muscle exercise (PFME) is the most common conservative management for urinary incontinence (UI) after radical prostatectomy (RP). However, whether the PFME guided by a therapist (G-PFME) can contribute to the recovery of urinary continence for patients after RP is still controversial. We performed this meta-analysis to investigate the effectiveness of G-PFME on UI after RP and to explore whether the additional preoperative G-PFME is superior to postoperative G-PFME alone. Literature search was conducted on Cochrane Library, Embase, Web of Science, and PubMed, to obtain all relevant randomized controlled trials published before March 1, 2018. Outcome data were pooled and analyzed with Review Manager 5.3 to compare the continence rates of G-PFME with control and to compare additional preoperative G-PFME with postoperative G-PFME. Twenty-two articles with 2647 patients were included. The continence rates of G-PFME were all superior to control at different follow-up time points, with the odds ratio (OR) (95% confidence interval [CI]) of 2.79 (1.53-5.07), 2.80 (1.87-4.19), 2.93 (1.19-7.22), 4.11 (2.24-7.55), and 2.41 (1.33-4.36) at 1 month, 3 months, 4 months, 6 months, and 12 months after surgery, respectively. However, there was no difference between additional preoperative G-PFME and postoperative G-PFME, with the OR (95% CI) of 1.70 (0.56-5.11) and 1.35 (0.41-4.40) at 1 month and 3 months after RP, respectively. G-PFME could improve the recovery of urinary continence at both early and long-term stages. Starting the PFME preoperatively might not produce extra benefits for patients at early stage, compared with postoperative PFME.