Application and Technique of Liquid Crystal-Based Biosensors

Luan, Chonglin; Luan, Haipei; Luo, Dawei

doi:10.3390/mi11020176

Cited by 55 publications

(37 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since the seminal work of Abbott and co-workers [169], liquid crystal sensors generally employ a molecularly triggered texture transition of a thermotropic liquid crystal from a dark to bright state (or vice versa) that indicates the absorption of a number of liquid, gas, or biological molecules within the liquid crystal [170]. But, there have also been some reports of lyotropic LC being used for sensing, for example chromonics for biological sensing applications [171], or lyotropic phases of DNA for enzymes [172] and other for antigens [173] and pathogens [174].…”

Section: Applicationsmentioning

confidence: 99%

Novel Trends in Lyotropic Liquid Crystals

Dierking

Neto

2020

Crystals

View full text Add to dashboard Cite

We introduce and shortly summarize a variety of more recent aspects of lyotropic liquid crystals (LLCs), which have drawn the attention of the liquid crystal and soft matter community and have recently led to an increasing number of groups studying this fascinating class of materials, alongside their normal activities in thermotopic LCs. The diversity of topics ranges from amphiphilic to inorganic liquid crystals, clays and biological liquid crystals, such as viruses, cellulose or DNA, to strongly anisotropic materials such as nanotubes, nanowires or graphene oxide dispersed in isotropic solvents. We conclude our admittedly somewhat subjective overview with materials exhibiting some fascinating properties, such as chromonics, ferroelectric lyotropics and active liquid crystals and living lyotropics, before we point out some possible and emerging applications of a class of materials that has long been standing in the shadow of the well-known applications of thermotropic liquid crystals, namely displays and electro-optic devices.

show abstract

Section: Applicationsmentioning

confidence: 99%

Novel Trends in Lyotropic Liquid Crystals

Dierking

Neto

2020

Crystals

View full text Add to dashboard Cite

show abstract

“…Hence, LC shows great potential for toxicant detection, environmental monitoring, and disease diagnosis. To date, a number of groups have reviewed the general components and applications related to LC-based biosensors [ 20 , 21 , 22 , 23 ]. There are still some missing parts that are worth discussing, such as LC sensing of chemical compounds and machine-learning-assisted LC sensing technology.…”

Section: Introductionmentioning

confidence: 99%

State-of-the-Art Development in Liquid Crystal Biochemical Sensors

et al. 2022

View full text Add to dashboard Cite

As an emerging stimuli-responsive material, liquid crystal (LC) has attracted great attentions beyond display applications, especially in the area of biochemical sensors. Its high sensitivity and fast response to various biological or chemical analytes make it possible to fabricate a simple, real-time, label-free, and cost-effective LC-based detection platform. Advancements have been achieved in the development of LC-based sensors, both in fundamental research and practical applications. This paper briefly reviews the state-of-the-art research on LC sensors in the biochemical field, from basic properties of LC material to the detection mechanisms of LC sensors that are categorized into LC-solid, LC–aqueous, and LC droplet platforms. In addition, various analytes detected by LCs are presented as a proof of the application value, including metal ions, nucleic acids, proteins, glucose, and some toxic chemical substances. Furthermore, a machine-learning-assisted LC sensing platform is realized to provide a foundation for device intelligence and automatization. It is believed that a portable, convenient, and user-friendly LC-based biochemical sensing device will be achieved in the future.

show abstract

“…Liquid crystal (LC) sensing platforms have been developed by exploiting the inherent optical and dielectric anisotropies of LCs, whose molecules are reoriented while interacting with analytes such as proteins, cancer markers, nucleic acids, metal ions, and other target molecules that are critical to the early detection of diseases and the assessment of environmental risks [1][2][3]. When the homeotropically (i.e., vertically) or homogeneously (i.e., planarly) aligned LC at the LC-aqueous or LC-solid interface was disturbed by an analyte, the interaction between LC molecules and the transmitted light was altered as well.…”

Section: Introductionmentioning

confidence: 99%

Quantitative Biosensing Based on a Liquid Crystal Marginally Aligned by the PVA/DMOAP Composite for Optical Signal Amplification

Chang

Lee

2022

Biosensors

View full text Add to dashboard Cite

The working principle for a liquid crystal (LC)-based biosensor relies on the disturbance in the orderly aligned LC molecules induced by analytes at the LC-aqueous or LC-solid interface to produce optical signals that can be typically observed under a polarizing optical microscope (POM). Our previous studies demonstrate that such optical response can be enhanced by imposing a weak electric field on LCs so that they are readily tilted from the homeotropic alignment in response to lower concentrations of analytes at the LC-glass interface. In this study, an alternative approach toward signal amplification is proposed by taking advantage of the marginally tilted alignment configuration without applying an electric field. The surface of glass substrates was modified with a binary aligning agent of poly(vinyl alcohol) (PVA) and dimethyloctadecyl[3-(trimethoxysilyl)propyl] ammonium chloride (DMOAP), in which the amount of PVA was fine-tuned so that the interfacing LC molecules were slightly tilted but remained virtually homeotropically aligned to yield no light leakage under the POM in the absence of an analyte. Two nematic LCs, E7 and 5CB, were each sandwiched between two parallel glass substrates coated with the PVA/DMOAP composite for the detection of bovine serum albumin (BSA), a model protein, and cortisol, a small-molecule steroid hormone. Through image analysis of the optical appearance of E7 observed under the POM, a limit of detection (LOD) of 2.5 × 10−8 μg/mL for BSA and that of 3 × 10−6 μg/mL for cortisol were deduced. Both values are significantly lower than that obtained with only DMOAP as the alignment layers, which correspond to signal amplification of more than six orders of magnitude. The new approach for signal amplification reported in this work enables analytes of a wide range of molecular weights to be detected with high sensitivity.

show abstract

Application and Technique of Liquid Crystal-Based Biosensors

Cited by 55 publications

References 59 publications

Novel Trends in Lyotropic Liquid Crystals

Novel Trends in Lyotropic Liquid Crystals

State-of-the-Art Development in Liquid Crystal Biochemical Sensors

Quantitative Biosensing Based on a Liquid Crystal Marginally Aligned by the PVA/DMOAP Composite for Optical Signal Amplification

Contact Info

Product

Resources

About