The detection of alpha-fetoprotein (AFP) in plasma is important in the diagnosis of hepatocellular carcinoma (HCC) in humans. We developed a biosensor to detect AFP in HCC patient plasma and in a phosphate buffer saline (PBS) solution using a graphene field-effect transistor (G-FET). The G-FET was functionalized with 1-pyrenebutyric acid N-hydroxysuccinimide ester (PBASE) for immobilization of an anti-AFP antibody. AFP was detected by assessing the shift in the voltage of the Dirac point (ΔV_Dirac) after binding of AFP to the anti-AFP-immobilized G-FET channel surface. This anti-AFP-immobilized G-FET biosensor was able to detect AFP at a concentration of 0.1 ng mL⁻¹ in PBS, and the detection sensitivity was 16.91 mV. In HCC patient plasma, the biosensor was able to detect AFP at a concentration of 12.9 ng mL⁻¹, with a detection sensitivity of 5.68 mV. The sensitivity (ΔV_Dirac) depended on the concentration of AFP in either PBS or HCC patient plasma. These data suggest that G-FET biosensors could have practical applications in diagnostics.

Although it is important to analyze the hemodynamic factors related to the right ventricle (RV) after left ventricular assist device (LVAD) implantation, previous studies have focused only on the alteration of the ventricular shape and lack quantitative analysis of the various hemodynamic parameters. Therefore, we quantitatively analyzed various hemodynamic parameters related to the RV under normal, heart failure (HF), and HF incorporated with continuous flow LVAD therapy by using a computational model. In this study, we combined a three-dimensional finite element electromechanical model of ventricles, which is based on human ventricular morphology captured by magnetic resonance imaging (MRI) with a lumped model of the circulatory system and continuous flow LVAD function in order to construct an integrated model of an LVAD implanted-cardiovascular system. To induce systolic dysfunction, the magnitude of the calcium transient function under HF condition was reduced to 70% of the normal value, and the time constant was reduced by 30% of the normal value. Under the HF condition, the left ventricular end systolic pressure decreased, the left ventricular end diastolic pressure increased, and the pressure in the right atrium (RA), RV, and pulmonary artery (PA) increased compared with the normal condition. The LVAD therapy decreased the end-systolic pressure of the LV by 41%, RA by 29%, RV by 53%, and PA by 71%, but increased the right ventricular ejection fraction by 52% and cardiac output by 40%, while the stroke work was reduced by 67% compared with the HF condition without LVAD. The end-systolic ventricular tension and strain decreased with the LVAD treatment. LVAD enhances CO and mechanical unloading of the LV as well as those of the RV and prevents pulmonary hypertension which can be induced by HF.

This study investigates the synthesis of ZrO_x-loaded NiFe₂O₄ photocatalysts (1, 2, and 3 wt%) through co-precipitation and wet impregnation methods for environmental and health applications. The structural analysis revealed a cubic crystal structure, with ZrO_x doping enhancing charge separation and mobility by converting the morphology from fibrous to needle-like. Under visible light (VL) and H₂O₂ activation, the ZrO_x(3 wt%)/NiFe₂O₄ composite achieved high degradation efficiencies (98.5% for Bisphenol A and 98.2% for 4-Nitrophenol) in 120 min via the Photo-Fenton mechanism. Kinetic analysis showed pseudo-first-order behavior with rate constants of 0.945 min⁻¹ for BPA and 0.904 min⁻¹ for 4-NP. The catalyst demonstrated stability with 91.5% efficiency retention after multiple cycles. DFT calculations indicated favorable HOMO-LUMO alignments and electrostatic potentials. Additionally, ZrO_x(3 wt%)/NiFe₂O₄ exhibited selective cytotoxicity against breast cancer cell lines, while maintaining high viability in HEK-293 cells. The results suggest that ZrO_x(3 wt%)/NiFe₂O₄ composites are promising for environmental and biomedical applications.

A reference electrode is necessary for the working of ion-sensitive field-effect transistor (ISFET)-type sensors in electrolyte solutions. The Ag/AgCl electrode is normally used as a reference electrode. However, the Ag/AgCl reference electrode limits the advantages of the ISFET sensor. In this work, we fabricated a two-channel graphene solution gate field-effect transistor (G-SGFET) to detect pH without an Ag/AgCl reference electrode in the electrolyte solution. One channel is the sensing channel for detecting the pH and the other channel is the reference channel that serves as the reference electrode. The sensing channel was oxygenated, and the reference channel was fluorinated partially. Both the channels were directly exposed to the electrolyte solution without sensing membranes or passivation layers. The transfer characteristics of the two-channel G-SGFET showed ambipolar field-effect transistor (FET) behavior (p-channel and n-channel), which is a typical characteristic curve for the graphene ISFET, and the value of V_Dirac was shifted by 18.2 mV/pH in the positive direction over the range of pH values from 4 to 10. The leakage current of the reference channel was 16.48 nA. We detected the real-time pH value for the two-channel G-SGFET, which operated stably for 60 min in the buffer solution.

The monitoring of Na⁺ ions distributed in the body has been indirectly calculated by the detection of Na⁺ ions in urine. We fabricated a two–dimensional (2D) Na⁺ ion sensor using a graphene ion–sensitive field–effect transistor (G–ISFET) and used fluorinated graphene as a reference electrode (FG–RE). We integrated G–ISFET and FG on a printed circuit board (PCB) designed in the form of a secure digital (SD) card to fabricate a disposable Na⁺ ion sensor. The sensitivity of the PCB tip to Na⁺ ions was determined to be −55.4 mV/dec. The sensor exhibited good linearity despite the presence of interfering ions in the buffer solution. We expanded the evaluation of the PCB tip to real human patient urine samples. The PCB tip exhibited a sensitivity of −0.36 mV/mM and linearly detected Na⁺ ions in human patient urine without any dilution process. We expect that G–ISFET with FG–RE can be used to realize a disposable Na⁺ ion sensor by serving as an alternative to Ag/AgCl reference electrodes.