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Exosome-templated nanoplasmonics for multiparametric molecular profiling
摘要： Exosomes are nanoscale vesicles distinguished by characteristic biophysical and biomolecular features; current analytical approaches, however, remain univariate. Here, we develop a dedicated platform for multiparametric exosome analysis—through simultaneous biophysical and biomolecular evaluation of the same vesicles—directly in clinical biofluids. Termed templated plasmonics for exosomes, the technology leverages in situ growth of gold nanoshells on vesicles to achieve multiselectivity. For biophysical selectivity, the nanoshell formation is templated by and tuned to distinguish exosome dimensions. For biomolecular selectivity, the nanoshell plasmonics locally quenches fluorescent probes only if they are target-bound on the same vesicle. The technology thus achieves multiplexed analysis of diverse exosomal biomarkers (e.g., proteins and microRNAs) but remains unresponsive to nonvesicle biomarkers. When implemented on a microfluidic, smartphone-based sensor, the platform is rapid, sensitive, and wash-free. It not only distinguished biomarker organizational states in native clinical samples but also showed that the exosomal subpopulation could more accurately differentiate patient prognosis.
关键词： molecular profiling,Exosomes,smartphone-based sensor,nanoplasmonics,biomarkers,microfluidic
更新于2025-09-23 15:21:01
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Silver Soret Nanoparticles for Femtomolar Sensing of Glutathione in a Surface Plasmon-Coupled Emission Platform
摘要： Surface plasmon-coupled emission (SPCE) has emerged as an interdisciplinary, versatile sensing platform due to its highly directional, solid-state and polarized emission. Here, we report the distinct properties rendered by Ag-Soret Colloids (Ag-SCs) such as nanovoids and nanocavities to observe 104-fold enhancement in emission intensity of omnidirectionally radiating emitter dipoles. Unlike earlier reports utilizing templated Ag-nanoparticles in spacer or cavity architectures, here we employ template-free, linker-less Ag-SCs. Purcell factor (PF - maximum of 120.6) obtained using the finite-difference time-domain (FDTD) simulations for soret nanocavities are in excellent agreement with the trend in emission enhancements obtained experimentally. Thermal gradient created by adiabatic cooling of Ag nanoparticles (AgNPs) drives their thermo-diffusion resulting in monodisperse nanoparticle assemblies (Ag-SCs). In addition, we report an extended-cavity architecture with Ag-SCs, as a novel pseudo-metal-dielectric-metal (p-MDM) interface, for achieving 80-fold SPCE. This study also features the unique properties of Ag-SCs as interfacial nanomaterials in SPCE platform to achieve femtomolar detection of glutathione (GSH). The quenching of fluorescence from alizarin red S-boric acid (ARS-BA) complex upon addition of Cu2+ ions and the dequenching upon GSH addition studied with Ag-SCs as spacer layer remarkably increased the sensitivity of the analyte. The uniform and intense electromagnetic field-confinement provided by these intricate architectures and hybrid interfaces, along with its ease of fabrication and versatility for variety of analytes, is critical to achieve augmented SPCE. This is accomplished without compromising on the reliability of detection as demonstrated with the use of a cellphone camera, CIE color space and luminosity plots for the turn-on fluorescence. The emission images were acquired using an android phone camera by aligning it with its angular emission, making it amenable for point-of-care diagnostics.
关键词： Soret colloids,Surface plasmon-coupled emission,spacer engineering,smartphone-based detection,template-free approach,fluorescence enhancement,glutathione sensing
更新于2025-09-23 15:19:57
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Smartphone-based critical angle refractometer for real-time monitoring of Brix value
摘要： We demonstrate the first smartphone-based critical angle refractometer for monitoring refractive index and Brix value in real time. The principle design of an optical coupler is based on the total internal reflection of incident light from the phone screen. The images acquired from the front-facing camera are directly analyzed on smartphone using a custom developed application, to detect the shift of gradient peak position corresponding to the refractive index and Brix value. Calibrations are carried out using nine water-sucrose solutions providing a linear response in the refractive index range of 1.3330-1.3575 RIU (R2 = 0.9984) with the sensitivity and the resolution of 2778.1 pixel/RIU, and 3.6′10-4 RIU, and a linear response in the Brix value of 0-16.25 °Brix (R2 = 0.9968) with the sensitivity and the resolution of 4.239 pixel/°Brix and 0.24 °Brix. We also successfully determined the sugar content in six fruit juices with the absolute error from standard refractometer at less than 0.21 °Brix.
关键词： refractive index,Critical angle refractometer,Brix value,smartphone-based
更新于2025-09-19 17:15:36
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Smartphone-based analytical biosensors
摘要： The traditional analytical biosensor instruments are relatively bulky, expensive, and not easy to handle, thus their applications are largely limited in resource-limited settings. The recent development of microfluidic lab-on-a-chip (LOC) technology has provided a possible solution to miniaturize the conventional biosensing system, yet other accessory devices to detect, readout, analyze, transfer, and display results are still required. With the rapid development, mass production, and pervasive distribution of smartphones in recent years, they have provided people with portable, cost-effective, and easy-to-operate platforms to build analytical biosensors for point-of-care (POC) applications and mobile health. Based on the common analytical methods, this paper reviews the recent development of four types of smartphone-based analytical biosensory systems at the POC, i.e., smartphone-based microscopic imaging, colorimetric, electrochemical, and electrochemiluminescence biosensor. The different bio-sensing strategies and analytical performance together with future perspectives are discussed.
关键词： point-of-care,smartphone-based biosensors,analytical methods,mobile health,microfluidic
更新于2025-09-19 17:15:36
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Point-of-care, smartphone-based, dual-modality, dual-view, oral cancer screening device with neural network classification for low-resource communities
摘要： Oral cancer is a growing health issue in a number of low- and middle-income countries (LMIC), particularly in South and Southeast Asia. The described dual-modality, dual-view, point-of-care oral cancer screening device, developed for high-risk populations in remote regions with limited infrastructure, implements autofluorescence imaging (AFI) and white light imaging (WLI) on a smartphone platform, enabling early detection of pre-cancerous and cancerous lesions in the oral cavity with the potential to reduce morbidity, mortality, and overall healthcare costs. Using a custom Android application, this device synchronizes external light-emitting diode (LED) illumination and image capture for AFI and WLI. Data is uploaded to a cloud server for diagnosis by a remote specialist through a web app, with the ability to transmit triage instructions back to the device and patient. Finally, with the on-site specialist’s diagnosis as the gold-standard, the remote specialist and a convolutional neural network (CNN) were able to classify 170 image pairs into ‘suspicious’ and ‘not suspicious’ with sensitivities, specificities, positive predictive values, and negative predictive values ranging from 81.25% to 94.94%.
关键词： convolutional neural network,screening device,oral cancer,low-resource communities,smartphone-based,autofluorescence imaging,white light imaging
更新于2025-09-09 09:28:46
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Paper-based Versatile SERS Chip with Smartphone-based Raman Analyzer for Point of Care Application
摘要： With the advanced development of the miniaturized Raman spectroscopy, surface enhanced Raman spectroscopy (SERS) has extended its applications into the field of Point of Care Testing (POCT) and demonstrated its great significance in virtue non-invasive property and capability of fingerprint identification. In the SERS-based analysis and/or sensing system, the preparation of low cost, high-performance SERS substrate is critically important. In this manuscript, vacuum filtration is utilized to fabricate the silver nanoparticles (AgNPs) embedded nylon filter membrane (ANFM) as flexible paper-based SERS chips. By characterizing the typical analytes with the miniaturized smartphone-based Raman analyzer, the proposed SERS chips have successfully demonstrated good sensitivity, repeatability and stability. The lowest concentration as detected can approach 1 pmol for Rhodamine 6G (RH6G) and 10 pmol for both crystal violet (CV) and malachite green (MG), respectively. With the help of microporous structure of the membrane, the ANFM based SERS chips can implement the separation of small molecules from complex mixture and can achieve “purified” SERS signals of targeted molecules. Besides, with the function of anti-friction resistance and flexibility, the ANFM can serve as SERS papers to pre-concentrate the contaminates by multiple swapping and further enhance the SERS signals for point of care analysis. Therefore, we demonstrate multi-functions of the flexible ANFM based SERS chips, which provides a promising solution for the POCT analysis with SERS technique on account of its flexibility and low fabrication cost.
关键词： silver nanoparticles,SERS chips,nylon filter membrane,Point of Care Testing,smartphone-based Raman analyzer,Surface-enhanced Raman spectroscopy
更新于2025-09-09 09:28:46
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Accuracy of a Smartphone-based Autorefractor Compared with Criterion-standard Refraction
摘要： SIGNIFICANCE: Uncorrected refractive error is a prevalent problem throughout the world especially among the low-income population who have limited access to professional eye care and cannot afford eyeglasses. PURPOSE: The purpose of this study was to evaluate the accuracy and usability of a low-cost, portable, smartphone-based autorefractor (Netra, EyeNetra Inc., Somerville, MA) in adults. METHODS: A cross-sectional study was conducted to compare the portable refractor with subjective (manifest and cycloplegic) refraction for sequential adult participants with best-corrected visual acuity of 20/40 or greater. For each method of refraction, the spherical equivalent was calculated. Differences between methods were tested with linear mixed regression models. A validated usability questionnaire was administered regarding ease of use (100-point scale, higher scores better) for the portable autorefractor. RESULTS: Eighty-seven subjects (152 eyes) were studied (age range, 20 to 90 years; mean ± standard deviation, 51.9 ± 18.3 years). Mean spherical equivalent by the portable device was ?2.76 D (range, ?14.75 to 3.63 D) compared with ?2.49 D (range, ?15.25 to 4.25 D) by manifest refraction. The mean relative difference in spherical equivalent between methods was ?0.27 D (P = .001, significantly different than 0 D). The mean absolute difference between methods was 0.69 D (P < .001, significantly different than 0.5-D absolute difference). Similar results were found when comparing spherical equivalent between Netra and cycloplegic refraction methods. Subjects reported average ease of use for the Netra of 75.4 ± 19.8. CONCLUSIONS: The portable autorefractor had small but clinically significant differences from subjective refraction. The device's scores on the usability scale indicate good overall patient acceptance. The device may be valuable for use where there is limited access to a trained refractionist.
关键词： autorefractor,portable,smartphone-based,low-cost,refractive error
更新于2025-09-04 15:30:14