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Free-label dual-signal responsive optical sensor by combining resonance Rayleigh scattering and colorimetry for sensitive detection of glutathione based on ultrathin MnO2 nanoflakes
摘要： Glutathione (GSH) plays a critical role in the living system and its abnormalities are closely associated with numerous clinical diseases. Thus, monitoring and detecting the content of GSH in the living system is still of great importance. Herein, a novel dual-signal responsive optical sensor is developed by using resonance Rayleigh scattering (RRS) and colorimetry for sensitive detection of GSH. In this sensor, MnO2 nanoflakes are used as both GSH recognizer and signal transducer of RRS and colorimetry. The solution of MnO2 nanoflakes shows strong RRS and absorption signals because MnO2 nanoflakes possess a large surface area and high molar extinction coefficient. However, MnO2 can be reduced to Mn2+ and MnO2 nanoflakes can be etched to small nanoparticles by GSH, causing both the RRS and absorption signals to decrease. Based on the change of RRS signal and absorbance of MnO2 nanoflakes, a novel dual-signal responsive optical sensor is successfully constructed to detect the content of GSH. The as-developed optical sensor toward GSH presents a favorable sensitivity with a detection limit of 0.033 and 0.67 μM for RRS and colorimetry, respectively. Furthermore, the as-developed approach is straightforward, quickly responsive, free-label, and cost-effective. More significantly, this method combines the advantages of RRS and colorimetry for the detection of GSH. Beyond this, the proposed RRS method has also been successfully utilized to detect the content of GSH in glutathione injection samples.
关键词： Glutathione,Resonance Rayleigh scattering,MnO2 nanoflakes,Colorimetry,Dual-signal
更新于2025-11-14 17:04:02
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Study on sliding-window length based on Rayleigh backscattering spectrum correlation in distributed optical-fiber strain measurement
摘要： A theoretical model is established for estimating the strain measurement error based on the Rayleigh backscattering spectrum correlation in distributed optical fiber strain measurements. Assuming the signal is much larger than the noise, the theoretical model predicts the strain measurement error using noise variance and the defined quality factor Q of the Rayleigh backscattering spectrum. Furthermore, an algorithm based on the quality factor Q is proposed to select an optimized sliding-window. The sliding-window length can be obtained by calculating the threshold value of the quality factor using a theoretical model corresponding to the required strain measurement accuracy. Compared with the traditional method where the sliding-window length is defined by the user based on spatial resolution requirements or an empirical definition, the sliding-window length determined by the algorithm is more reasonable and can be automatically defined, alleviating the requirement for user inputs. To verify the correctness of the theoretical model, two experiments are set up: a self-correlation experiment, that analyzes the effect of the quality factor on the strain measurement accuracy, and a virtual experiment of the noise influence, which analyzes the effect of different noise variances. The experimental results are in good agreement with those of the model.
关键词： Distributed optical fiber strain measurement,Rayleigh backscattering spectrum correlation,Optical frequency domain reflectometer
更新于2025-09-23 15:23:52
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Modern description of Rayleigh's criterion
摘要： Rayleigh’s criterion states that it becomes essentially difficult to resolve two incoherent optical point sources separated by a distance below the width of point spread functions (PSFs), namely, in the subdiffraction limit. Recently, researchers have achieved superresolution for two incoherent point sources with equal strengths, surpassing Rayleigh’s criterion. However, situations where more than two point sources needed to be resolved have not been fully investigated. Here we prove that for any incoherent sources with arbitrary strengths, a one- or two-dimensional (1D or 2D) image can be precisely resolved up to its second moment in the subdiffraction limit, i.e., the Fisher information (FI) is nonzero. But the FI with respect to higher order moments always tends to zero polynomially as the size of the image decreases, for any type of nonadaptive measurement. We call this phenomenon a modern description of Rayleigh’s criterion. For PSFs under certain constraints, the optimal measurement basis estimating all moments in the subdiffraction limit for 1D weak-source imaging is constructed. Such a basis also generates the optimal-scaling FI with respect to the size of the image for 2D or strong-source imaging, which achieves an overall quadratic improvement compared to direct imaging.
关键词： Fisher information,optical imaging,Rayleigh's criterion,superresolution,incoherent sources,subdiffraction limit
更新于2025-09-23 15:23:52
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Influence of the Ply Angle Deviation on the Out-of-Plane Deformation of the Composite Space Mirror
摘要： In order to discuss the influence of the ply angle deviation, six symmetric quasi-isotropic layup sequences imposed the fixed or random angle deviation were studied based on the numerical analysis, such as Monte Carlo stochastic finite element method and statistic analysis. The out-of-plane deformation was observed in spite of the symmetric quasi-isotropic sequences subjected to a temperature change due to the ply angle deviation in the space mirror. The surface peak-to-valley (PV), which is one kind of out-of-plane deformation, is proportional to the magnitude of the fixed angle deviation, and the mean of PVs is also proportional to the standard deviation of the random angle deviation. The out-of-plane deformation resulting from two-ply angle deviation indirectly satisfies the parallelogram law, and if each ply angle deviation is random independently, the probability density of that satisfies the Rayleigh distribution. In this paper, it is found that the most effective method to improve the surface accuracy of the space mirror is decreasing the standard deviation of the angle deviation, next to decreasing ply thickness and optimizing layup sequence, which is useful for application in the space mirror.
关键词： Rayleigh distribution,MCSFEM,Out-of-plane deformation,Mirror,CFRP
更新于2025-09-23 15:23:52
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Resonance Rayleigh Scattering Method for the Determination of Green Food DNA Based on the Interaction of O-hydroxyphenylfluorone with DNA
摘要： A new spectroscopic analysis method was built for the determination of green food DNA based on the interaction of o-Hydroxyphenylfluorone (o-HPF) with DNA using the resonance Rayleigh Light Scattering (RLS) technique. In the Tris-HCl buffer at pH 8.1, the RLS signal of o-HPF was enhanced remarkably in the presence of DNA and the enhanced RLS intensity at 519 nm was in direct proportion to DNA concentration in the range of 0.02-1.8×10-5 g/L with a good linear relationship. The detection limit was 4.6×10-8 g/L. The method was simple, rapid and high accuracy which had been applied to the determination of green food DNA in sample with satisfactory results.
关键词： Green food DNA,o-HPF,resonance rayleigh light scattering
更新于2025-09-23 15:22:29
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Efficient method to calculate the optical quantities of multi-layer systems with randomly rough boundaries using the Rayleigh-Rice theory
摘要： An efficient and numerically stable method for calculating the optical quantities of multi-layer systems with slightly rough boundaries using the second order Rayleigh–Rice theory is developed. It is assumed that the mean planes of the boundaries are parallel and all the media forming the system are nonmagnetic, isotropic and homogeneous. The perturbation series is formulated using the four-dimensional formalism inspired by the Yeh matrix formalism, but the final result is written using the two-dimensional formalism which is more efficient for the numerical calculations. The final formulae, which are expressed using an arbitrary power spectral density function, include the mixing between the p and s polarizations occurring for anisotropic roughness. Although in the general case the calculation of optical quantities requires evaluation of double integrals, it is shown that for the power spectral density function given by the isotropic Gaussian function some integrals can be calculated analytically and only single integrals have to be evaluated numerically. The random roughness of boundaries is a defect that occurs frequently in practice, and it must be taken into account in the optical characterization and synthesis of thin film systems exhibiting this defect. The presented method is suitable for these purposes, since both of the mentioned applications require methods that are very fast.
关键词： multi-layer systems,optical quantities,Rayleigh–Rice theory,random boundary roughness
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Ultrasonics Symposium (IUS) - Kobe, Japan (2018.10.22-2018.10.25)] 2018 IEEE International Ultrasonics Symposium (IUS) - SH-Type Spurious Response Free TC-SAW Resonators Using Low Acoustic Velocity Rayleigh SAW on LiNbO<inf>3</inf> Substrate
摘要： In this paper, we describe the behavior of the spurios resonance caused by shear-horizontal (SH) type surface acoustic wave (SAW) devices in low acoustic velocity (LAV) Rayleigh-type SAW structures. It is well known that an SH-type SAW or Rayleigh-type SAW device appears near the main resonance on LiNbO3 (LN) substrates, which causes various undesired effects on the device characteristics. However, they are often non-negligible in practical use. In order to explore a solution of this problem, we theoretically and experimentally investigated the variation of the SH-type SAW resonance in the low acoustic velocity (LAV) Rayleigh-type SAW structure on LN substrates, which is a new LAV-SAW structure with a higher performance temperature-compensated (TC) SAW device (TC-SAW) technology. As a result, we revealed that the SH-type SAW can be almost zero even if various parameters are changed. Moreover, very small sized and TC-SAW devices can be realized using this new technology.
关键词： temperature compensation,SAW,Rayleigh-type SAW,acoustic velocity,LiNbO3,SH-type SAW
更新于2025-09-23 15:22:29
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Transforming the Fiber-Optic Network into a Dense and Ultrasensitive Seismic Sensor Array
摘要： We show a technology capable of performing position-resolved measurement of nanostrain perturbations along a conventional optical fiber cable, with meter-scale resolution. This technology can be deployed in already existing networks to achieve a dense and ultrasensitive seismic sensor array. Applications ranging from seismic protection to chemical sensing are explored.
关键词： seismology,distributed fiber optics sensors,Rayleigh scattering,optical time domain reflectometry,distributed acoustic sensors
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Ultrasonics Symposium (IUS) - Kobe, Japan (2018.10.22-2018.10.25)] 2018 IEEE International Ultrasonics Symposium (IUS) - Looking at the Skull in a New Light: Rayleigh-Lamb Waves in Cranial Bone
摘要： Current knowledge on the ultrasound wave propagation in the cranial bone is restricted to far-field observations. In order to extend our understanding on how ultrasound waves propagate in the skull, we use short laser pulses to excite ultrasound waves in water-immersed ex vivo mouse and human skulls and explored their near-field. The laser pulses ( 10 ns duration) of 532 nm are absorbed by a small layer of black burnish deposited on the skull’s inner surface and generate ultrasound waves due to the thermoelastic effect. The acoustic near-field is mapped using a needle hydrophone close to the skull surface, following a three-dimensional scanning path derived from a previous pulse-echo scan of the skull with a spherically focused ultrasound transducer. The results for mouse and human skulls show different wave propagation regimes according to their differences in size, thickness, and internal structure. Leaky and non-leaky waves have been observed for both skull samples. Zero order Lamb modes were observed in the mouse skull, whereas Rayleigh-Lamb higher order modes can be observed in the human skull sample, presumably propagating in the outer cortical bone layer. Good agreement is found between the experiments and the multilayered flat plate model.
关键词： Skull Bone,Lamb Waves,Near Field,Surface Acoustic Waves,Rayleigh Waves,Plate waves,Laser ultrasonics
更新于2025-09-23 15:22:29
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[ACM Press the 2017 2nd International Conference - Wuhan, China (2017.11.07-2017.11.09)] Proceedings of the 2017 2nd International Conference on Communication and Information Systems - ICCIS 2017 - Effect of Concentration on Surface Acoustic Wave Velocity in A Rayleigh-type Biosensor
摘要： To predict the propagation velocity of different concentrations of bovine serum albumin (BSA) in a Rayleigh-type biosensor, we derived a new calculation method for a Rayleigh surface acoustic wave (SAW) device. The method can calculate propagation velocities of leaky Rayleigh waves and Rayleigh waves when liquid is placed in the groove of a Rayleigh-type SAW device. Different concentration of BSA proteins were used to evaluate the effect of these concentrations. In this study, we used different concentrations of BSA and a Rayleigh-type SAW device consisted of grooves of 0.25 mm width and 0.26 mm height and grooves of 0.40 mm width and 0.25 mm height, quartz as the substrate and interdigital transducers (IDT) with a 25.00 mm distance. The frequency of the Rayleigh-type SAW device was set to 157.6 MHz. Our data suggests that the propagation velocity of SAWs depends mainly upon BSA protein concentration and the size of groove. At the same concentration of BSA, the propagation acoustic wave velocity of BSA depends on the size of groove. The results showed the 0.40 mm width-0.25 mm height groove was more suitable than the 0.25 mm width-0.26 mm height groove for studying the propagation velocity of wave with liquid in a Rayleigh-type SAW device. With the propagation velocity decreased when the concentration of BSA protein increased.
关键词： Surface acoustic wave (SAW),Rayleigh-type SAW device,Leaky Rayleigh wave,Bovine serum albumin (BSA),Rayleigh wave
更新于2025-09-23 15:21:01