arXiv subjects

Shuoying Zhao

Publications and source records attributed to Shuoying Zhao.

4 recordsLinked to original sources

arXiv2025

Solvatochromic microcavity ion sensors

A novel copper(II) ion sensor has been developed, achieving both a broad dynamic range and high sensitivity, effectively addressing the limitations of conventional fluorescence-based detection methods. The sensor exploits the hydrolysis reaction between rhodamine B hydrazide (RBH) and copper(II) ions, with optical signal amplification enabled by a whispering-gallery-mode (WGM) microcavity laser. By adjusting the solvent type and utilizing the solvatochromic effect, the detection range of the copper(II) ion and RBH reaction was optimized. The sensor enables rapid, broad dynamic range detection of copper(II) ions, spanning from 5 uM to 3 mM, with a high selectivity, which holds significant potential for future applications in environmental monitoring and biomedical fields.

physics.optics↗

arXiv2025

Ultrasensitive Label-free Detection of Human CEACAM5 using a WGM Resonator Based on Thin-walled Capillary

Whispering gallery mode (WGM) laser sensors, utilizing the interaction between the in-plane evanescent field and the surface vicinity, provide enhanced sensitivity in label-free sensing for bioanalysis and disease screening. However, the unavoidably excited spiral modes resulting from the weak axial confinement and their sensing potential were overlooked. In this study, a microfluidic biosensor using the localized conical modes of an active resonator based on the thin-walled capillaries was developed, demonstrating ultrasensitive refractive index and biomolecule detection capabilities. This sensor provides nonspecific detection of bovine serum albumin (BSA) and specific detection of Carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) with ultra-low detection limits, large sensing range, rapid response, and a cost-effective design, making it a promising candidate for industrial-scale production. The theoretical detection limit for CEACAM5 is as low as 0.38ag/mL (5zM), and the sensitivity in the linear region reaches 0.25nm/(ag/mL). These results are approximately an order of magnitude higher in sensitivity than currently reported active WGM biosensors, demonstrating enormous detection potential for biomarkers.

physics.optics↗

arXiv2023

An mCherry biolaser based on microbubble cavity with ultra-low threshold

Biolasers show considerable potential in the biomedical field. Fluorescent protein (FP) is a type of biomaterial with good luminescence efficiency that can be used as the luminescent gain medium in biolasers. Due to the higher cell/tissue permeability, lower cell phototoxicity, and relatively less background fluorescence than other fluorescent proteins, the red fluorescent protein is more suitable in biological applications. MCherry is the most extensively used high-quality red fluorescent protein because of its short maturation time and stable luminescence properties. In this study, using mCherry and microbubble cavity, we realize a highly stable mCherry fluorescent protein laser. The laser resonator achieves a quality factor of 10^8, which is the highest Q factor among the currently available FP lasers. Moreover, this laser exhibits low threshold of 286 fJ, which can effectively protect the luminescent material from being damaged by pump light. Such a threshold is the lowest in the FP lasers as per our knowledge. The prepared laser shows excellent stability in a wide pH range with good photobleaching resistance and can be stored at 4 degree for nearly a month. Also, the laser can serve as a high-sensitivity molecular concentration detector with mCherry as biomarker, owing to its lasing threshold behavior.

physics.optics↗

arXiv2022

Ultralow-threshold green fluorescent protein laser based on high Q microbubble resonators

Biological lasers have attracted vast attention because of their potential medical application prospects, especially the low threshold biological laser, which can be used for ultrasensitive biological detection while ensuring that its luminous gain medium is not damaged by the high-energy pump light. By coupling the low concentration green fluorescent protein (GFP) solution with a high Q whispering gallery mode microbubble resonator, we managed to fabricate a miniature GFP laser with ultralow lasing threshold of 500 nJ/mm^2. The energy used to excite the GFP can be reduced to 380 fJ, two orders of magnitude lower than that of the lowest excitation energy GFP laser known. The Q value of the optical cavity in this biological laser is 5.3 x 10^7, the highest among GFP lasers at present. We further confirmed the long-term stability of the working characteristics of GFP laser for the first time and found that its optical characteristics can be maintained for at least 23 days. Finally, we measured the effects of different concentrations of fluorescent protein on the laser threshold. The data show that this biological laser can be used for a highly sensitive detection of GFP concentration.

physics.optics↗