Hyperboloid‐Drum Microdisk Laser Biosensors for Ultrasensitive Detection of Human IgG

Abstract

Whispering gallery mode (WGM) microresonators have been used as optical sensors in fundamental research and practical applications. The majority of WGM sensors are passive resonators that require complex systems, thereby limiting their practicality. Active resonators enable the remote excitation and collection of WGM‐modulated fluorescence spectra, without requiring complex systems, and can be used as alternatives to passive microresonators. This paper demonstrates an active microresonator, which is a microdisk laser in a hyperboloid‐drum (HD) shape. The HD microdisk lasers are a combination of a rhodamine B‐doped photoresist and a silica microdisk. These HD microdisk lasers can be utilized for the detection of label‐free biomolecules. The biomolecule concentration can be as low as 1 ag mL−1, whereas the theoretical detection limit of the biosensor for human IgG in phosphate buffer saline is 9 ag mL−1 (0.06 aM). Additionally, the biosensors are able to detect biomolecules in an artificial serum, with a theoretical detection limit of 9 ag mL−1 (0.06 aM). These results are approximately four orders of magnitude more sensitive than those for the typical active WGM biosensors. The proposed HD microdisk laser biosensors show enormous detection potential for biomarkers in protein secretions or body fluids.

Optical whispering-gallery mode barcodes for high-precision and wide-range temperature measurements

“…The results reveal opportunities in the study of transient thermal dynamics of physical and chemical processes. It is worth noting that our optical WGM sensor is not limited to thermal sensing; it can also be implemented in biochemical sensing [65][66][67][68][69] , nanoparticle detection [70][71][72] , magnetic detection [73][74][75] , photoacoustic detection 76,77 , and many other applications with a proper design. For a resonator-based magnetic field sensor, for instance, the resonance, coupling depth, and linewidth change with the magnetic field intensity 74,75 and therefore can be used as barcode features.…”

“…The WGM barcode technique integrates high-sensitivity, high-resolution, and large-dynamic-range measurement into a high-performance sensing platform without the need for extra complicated designs and expensive components. In addition, the technique can, in principle, be adopted for other types of optical resonant-based sensors with rich modal features, such as surface plasmon resonance sensors 67,78 , photonic crystal sensors 75,79 , inline fibre interferometers 34 , and even fluorescent and lasing-based sensors 68,80,81 . Therefore, our simple and general technique could have a variety of promising applications, ranging from physical thermodynamics to chemical thermodynamics, robotic sensing, and thermal phenomena in biomedical research.…”

Label-Free Optical Resonator-Based Biosensors

“…WGM biosensors are highly sensitive to changes in the surface conditions and refractive index, and they have been developed for single-molecule detection [ 20 , 21 , 115 ], pico- to atto-molar scale detection [ 21 , 112 , 113 , 116 , 117 , 118 , 119 , 120 , 121 ], and monitoring biological processes [ 122 , 123 , 124 , 125 , 126 ] or enzymatic reactions [ 127 , 128 ]. In recent studies, researchers have also taken advantage of geometric modifications [ 129 , 130 ] and material doping [ 116 , 118 , 119 , 131 , 132 , 133 , 134 ] to improve the Q-factors and sensitivity of WGM-based resonators. Geometric differences in most resonators may depend on fabrication capabilities or desired optical qualities, such as mode confinement, increased binding surface area, simpler fabrication techniques, or material choice.…”

“…Active WGM was demonstrated in a rhodamine-B doped silica microdisk in [ 116 ]. One advantage offered by active WGM devices over passive is natural excitation.…”

Исследование Чувствительности Микродискового Лазера К Изменению Показателя Преломления Окружающей Среды

“…Учитывая, что полуширина линии излучения составляет около 60 pm, мы можем заключить, что возможно детектирование минимального изменения показателя преломления на величину 0.006. Полученное значение спектрального сдвига позволяет судить о возможности создания биосенсоров, пригодных для детектирования таких веществ, как бычий сывороточный альбумин (BSA) или человеческий IgG (Human IgG), в концентрациях порядка pg/ml [13].…”