Three-dimensional (3D) printing technology provides a novel approach to material fabrication for various applications because of its ability to create low-cost 3D printed platforms. In this study, a printable graphene-based conductive filament was employed to create a range of 3D printed electrodes (3DEs) using a commercial 3D printer. This printing technology provides a simplistic and low-cost approach, which eliminates the need for the ex-situ modification and post-treatment of the product. The conductive nature of the 3DEs provides numerous deposition platforms for electrochemical active nanomaterials such as graphene, polypyrrole, and cadmium sulfide, either through electrochemical or physical approaches. To provide proof-of-concept, these 3DEs were physiochemically and electrochemically evaluated and proficiently fabricated into a supercapacitor and photoelectrochemical sensor. The as-fabricated supercapacitor provided a good capacitance performance, with a specific capacitance of 98.37 Fg−1. In addition, these 3DEs were fabricated into a photoelectrochemical sensing platform. They had a photocurrent response that exceeded expectations (~724.1 μA) and a lower detection limit (0.05 μM) than an ITO/FTO glass electrode. By subsequently modifying the printing material and electrode architecture, this 3D printing approach could provide a facile and rapid manufacturing process for energy devices based on the conceptual design.

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We demonstrate refractive index sensors based on single mode tapered fiber and its application as a biosensor. We utilize this tapered fiber optic biosensor, operating at 1550 nm, for the detection of protein (gelatin) concentration in water. The sensor is based on the spectroscopy of mode coupling based on core modes-fiber cladding modes excited by the fundamental core mode of an optical fiber when it transitions into tapered regions from untapered regions. The changes are determined from the wavelength shift of the transmission spectrum. The proposed fiber sensor has sensitivity of refractive index around 1500 nm/RIU and for protein concentration detection, its highest sensitivity is 2.42141 nm/%W/V.

In this work, sensitive detection of dengue virus type 2 E-proteins (DENV-2 E-proteins) was performed in the range of 0.08 pM to 0.5 pM. The successful DENV detection at very low concentration is a matter of concern for targeting the early detection after the onset of dengue symptoms. Here, we developed a SPR sensor based on self-assembled monolayer/reduced graphene oxide-polyamidoamine dendrimer (SAM/NH 2 rGO/PAMAM) thin film to detect DENV-2 E-proteins. Surface characterizations involving X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) confirms the incorporation of NH 2 rGO-PAMAM nanoparticles in the prepared sensor films. The specificity, sensitivity, binding affinity, and selectivity of the SPR sensor were then evaluated. Results indicated that the variation of the sensing layer due to different spin speed, time incubation, and concentration provided a better interaction between the analyte and sensing layer. The linear dependence of the SPR sensor showed good linearity (R 2 = 0.92) with the lowest detection of 0.08 pM DENV-2 E-proteins. By using the Langmuir model, the equilibrium association constant was obtained at very high value of 6.6844 TM −1 (R 2 = 0.99). High selectivity of the SPR sensor towards DENV-2 E-proteins was achieved in the presence of other competitors. Dengue virus (DENV) is the most common arthropod-borne viral disease that poses a serious global problem. According to World Health Organization (WHO), the dengue virus is the leading cause of death of 22 000, annually. As of today, the need for hospitalization and medical treatment are constantly dense due to the fact that 390 million people in the world are still infected with DENV 1. Its four distinct serotypes (DENV-1. DENV-2, DENV-3, and DENV-4) are capable of causing a range of clinical symptoms ranging from mild fevers to the severe dengue haemorrhagic fever (DHF) and be potentially life-threatening 2-10. Despite its large burden to human health, no effective vaccine and antiviral therapy are available for the virus 11,12. Early treatment for DENV is only by maintaining the body fluid of the patient, as it is critical in fighting the severe symptoms of DENV 13,14. Hence, an early, rapid, and accurate diagnosis at the onset of infection is the demand of the day in the most epidemic settings. Present discoveries in dengue diagnostics that can help in the early diagnosis are targeting the host-virus itself. DENV consists of a single-stranded positive-sense RNA virus that encodes 10 different types of proteins. Seven of

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Wideband multiwavelength Brillouin-Erbium fiber laser (BEFL) utilizing a linear cavity is presented, highlighting the usage of higher Brillouin and lower erbium doped-fiber pump powers to achieve higher lasing spectral bandwidth. A tuning range of 60 nm has been obtained from 1525 to 1585 nm. The dependency of the Stokes signal tuning range on the laser's pumping power is also elaborated. The wide tuning range of the proposed BEFL has potential in dense wavelength division multiplexing communication systems.

Dengue viral infection is one of the most common deadliest diseases and has become a recurrent issue for public health in tropical countries. Although the spectrum of clinical diagnosis and treatment have recently been established, the efficient and rapid detection of dengue virus (DENV) during viremia and the early febrile phase is still a great challenge. In this study, a dithiobis (succinimidyl undecanoate, DSU)/amine-functionalized reduced graphene oxide-–polyamidoamine dendrimer (DSU/amine-functionalized rGO–PAMAM) thin film-based surface plasmon resonance (SPR) sensor was developed for the detection of DENV 2 E-proteins. Different concentrations of DENV 2 E-proteins were successfully tested by the developed SPR sensor-based system. The performance of the developed sensor showed increased shift in the SPR angle, narrow full-width–half-maximum of the SPR curve, high detection accuracy, excellent figure of merit and signal-to-noise ratio, good sensitivity values in the range of 0.08–0.5 pM (S = 0.2576°/pM, R2 = 0.92), and a high equilibrium association constant (KA) of 7.6452 TM−1. The developed sensor also showed a sensitive and selective response towards DENV 2 E-proteins compared to DENV 1 E-proteins and ZIKV (Zika virus) E-proteins. Overall, it was concluded that the Au/DSU/amine-functionalized rGO–PAMAM thin film-based SPR sensor has potential to serve as a rapid clinical diagnostic tool for DENV infection.

We investigate the amplitude flatness of Rayleigh-assisted Brillouin-Raman comb laser in a linear cavity in which feedbacks are formed by high-reflectivity mirror. The optimization of Brillouin pump power and wavelength is very crucial in order to obtain a uniform power level between Stokes lines. The Brillouin pump must have a relatively large power and its wavelength must be located closer to the Raman peak gain region. The flat-amplitude bandwidth is also determined by the choice of Raman pump wavelengths. A flat-amplitude bandwidth of 30.7 nm from 1527.32 to 1558.02 nm is measured when Raman pump wavelengths are set to 1435 and 1450 nm. 357 uniform Brillouin Stokes lines with 0.086 nm spacing are generated across the wavelength range. The average signal-to-noise ratio of 17 dB is obtained for all the Brillouin Stokes lines.