The outbreak of the influenza virus (H1N1) has symptoms such as coughing, fever, and a sore throat, and due to its high contagious power, it is fatal to humans. To detect H1N1 precisely, the present study proposed an electrochemical biosensor composed of a multifunctional DNA four-way junction (4WJ) and carboxyl molybdenum disulfide (carboxyl-MoS₂) hybrid material. The DNA 4WJ was constructed to have the hemagglutinin aptamer on the head group (recognition part); each of the two arms has four silver ions (signal amplification part), and the tail group has an amine group (anchor). This fabricated multifunctional DNA 4WJ can specifically and selectively bind to hemagglutinin. Moreover, the carboxyl-MoS₂ provides an increase in the sensitivity of this biosensor. Carboxyl-MoS₂ was immobilized using a linker on the electrode, followed by the immobilization of the multifunctional 4WJ on the electrode. The synthesis of carboxyl-MoS₂ was confirmed by field emission scanning electron microscopy (FE-SEM), and the surface of the electrode was confirmed by atomic force microscopy. When H1N1 was placed in the immobilized electrode, the presence of H1N1 was confirmed by electrochemical analysis (cyclic voltammetry, electrochemical impedance spectroscopy). Through selectivity tests, it was also possible to determine whether this sensor responds specifically and selectively to H1N1. We confirmed that the biosensor showed a linear response to H1N1, and that H1N1 could be detected from 100 nM to 10 pM. Finally, clinical tests, in which hemagglutinin was diluted with human serum, showed a similar tendency to those diluted with water. This study showed that the multi-functional DNA 4WJ and carboxyl-MoS₂ hybrid material can be applied to a electrochemical H1N1 biosensor.

In the present study, we propose a novel biosensor platform using a gold-tellurium (Au–Te) nanoworm structure through surface-enhanced Raman spectroscopy (SERS). Au–Tenanoworm was synthesized by spontaneous galvanic replacement of sacrificial Te nanorods templated with Au (III) cations under ambient conditions. The fabricated Au–Te nanoworm exhibited an interconnected structure of small spherical nanoparticles and was found to be effective at enhancing Raman scattering. The Au–Te nanoworm-immobilized substrate exhibited the ability to detect thyroxine using an aptamer-tagged DNA three-way junction (3WJ) and glycoprotein 120 (GP120) human immunodeficiency virus (HIV) using an antibody. The modified substrates were investigated by scanning electron microscopy and atomic force microscopy (AFM). The optimal Au–Te nanoworm concentration and immobilization time for the thyroxine biosensor platform were further determined by SERS experimentation. Thus, the present study showed that the Au–Te nanoworm structure could be applied to various biosensor platforms.

With the acceleration of the Fourth Industrial Revolution, the development of information and communications technology requires innovative information storage devices and processing devices with low power and ultrahigh stability. Accordingly, bioelectronic devices have gained considerable attention as a promising alternative to silicon-based devices because of their various applications, including human-body-attached devices, biomaterial-based computation systems, and biomaterial–nanomaterial hybrid-based charge storage devices. Nanomaterial-based charge storage devices have witnessed considerable development owing to their similarity to conventional charge storage devices and their ease of applicability. The introduction of a biomaterial-to-nanomaterial-based system using a combination of biomolecules and nanostructures provides outstanding electrochemical, electrical, and optical properties that can be applied to the fabrication of charge storage devices. Here, we describe the recent advances in charge storage devices containing a biomolecule and nanoparticle heterolayer including (1) electrical resistive charge storage devices, (2) electrochemical biomemory devices, (3) field-effect transistors, and (4) biomemristors. Progress in biomolecule–nanomaterial heterolayer-based charge storage devices will lead to unprecedented opportunities for the integration of information and communications technology, biotechnology, and nanotechnology for the Fourth Industrial Revolution.