Biomarker assay has evolved into an invaluable complementary method for early screening and treatment diagnosis of tumors. Limited by the bulky devices, elaborate procedures, and poor detection accuracy, conventional methods fail to meet the demand for portable, universal, as well as high-precision detection. Herein, an optical fiber lossy mode resonance (LMR) immunoprobe implemented by ITO film as the lossy mode support layer is demonstrated for the detection of prostate-specific antigen (PSA), a biomarker for prostate cancer (PCa). Theoretically, the refractive index sensing performance of the optical fiber LMR was verified by constructing a transmission matrix model, providing theoretical guidance for the application of optical fiber LMR sensors. The construction of the PSA immunoprobe was experimentally achieved by functionalizing the optical fiber LMR sensor. The relationship between wavelength shift and PSA concentration was quantified by resonance wavelength interrogation, and the detection limit (LOD) was calculated to be as low as 0.144 ng/mL, making it ideal for early risk management and prognostic diagnosis of PCa. For clinical application, multiple serum samples were analyzed by the optical fiber LMR immunoprobe with favorable precision. Taken together, this work demonstrates considerable promise in applications of label-free, low-cost, compact-size, and convenient early screening for suspected PCa.
Lithium-ion batteries (LIBs) experience intense electrochemical reactions during high-rate charge/discharge cycles, resulting in significant differences in state characteristics between the inside and outside of the battery. However, most monitoring techniques are severely limited in safety and accuracy due to the intense redox reactions inside LIBs. Thus, we propose a highly stable fibre-optic microcavity sensor based on the Fabry-Perot (F-P) interference principle, which is capable of real-time, in-situ monitoring of the state characteristics inside the LIBs. The degree of electrochemical reactions inside the battery is reflected by extracting the internal gas pressure state characteristics of LIBs at different charging and discharging rates. This experimental result demonstrates that the voltage is closely related to the gas pressure inside the battery and that the cyclic gas pressure increases greatly with the charge/discharge rate increase. This fibre-optic sensing approach provides a promising tool for monitoring in-situ battery state characteristics and safety.
Phase interrogation method can effectively avoid the operational spacing problems of fiber-optic Fabry-Perot (F-P)sensors. Based on the principles of F-P interference and low coherence interference, polarizers and birefringent crystals are applied to construct signals with quadrature relationship. A four-quadrant inverse tangent operation is employed to accurately calculate the phase values. We have performed rapid, high-speed measurements of dynamic pressure with aF-P sensor. Experimental results show that the method can achieve real-time pressure measurements up to 3 MPa with an interrogation rate of 5 kHz. This research holds much promise for the promotion of interferometric based fiber-optic sensors and applications of pressure measurements.
Indium tin oxide (In2O3-SnO2-90/10 wt%, ITO) is a semiconductor material with excellent electrical conductivity. In this paper, ITO was deposited on a multimode optical fiber by magnetron sputtering technique and characterized by using Scanning Electron Microscopy (SEM). It is subsequently used as a working electrode in a three-electrode system to study its electrochemical behavior in different solutions. In 0.1 M KCl containing such redox probes as 1 mMofK3[Fe(CN)6] were discussed by Cyclic voltammetry (CV) method at different scan rates. The observed electrochemical processes are quasi-reversible and diffusion-controlled. The results of the investigation inject new vitality to enhance the intersection of electrochemistry and optics disciplines, and also lay the foundation for dual-domain determination.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.