Gold nanoparticle-mediated signal amplification of liquid crystal biosensors for dopamine

Abstract

A new design was developed for detection of dopamine using a boronic acid based amphiphile at aqueous–liquid crystal interface. The detection was highly enhanced in presence of gold nanoparticles.

Gold nanostructures: synthesis, properties, and neurological applications

“…For example, neurotransmitters (like dopamine) respond rapidly (within only a few milliseconds) to a stimulus, while neuromodulators (like ascorbic acid) respond more slowly to affect the required message between presynaptic terminals and target cells. [286][287][288][289][290][291] In this section, we review different types of goldbased biosensors, which have recently been developed to detect or monitor various neurochemicals in vitro or in vivo. [292][293][294][295][296][297] The efficiency of electrochemical methods could be improved using GNSs for ultra-sensitive determination of different neurological molecules.…”

Simultaneous Detection of Multiple Tumor Markers in Blood by Functional Liquid Crystal Sensors Assisted with Target-Induced Dissociation of Aptamer

“…Liquid crystal (LC) sensors are a powerful and promising detection technique that can transduce and amplify chemical and biological events into visible optical signals with very high sensitivity by employing LCs as a sensing medium. − They have the advantages of not requiring intensive labor, molecular labels, or complex instrumentation, which makes them particularly attractive in developing portable and inexpensive devices for point-of-care diagnostics. − So far, most of the LC sensors only have been demonstrated to detect single tumor markers such as proteins and enzymes in buffer. − To the best of knowledge, simultaneous detection of multiple tumor markers, especially in blood, has not been achieved due to lack of a versatile strategy that can eliminate a potential matrix effect and cross-reactivity of probe/target sets, which greatly hinders practical applications of LC sensors.…”

A Single-Substrate Biosensor with Spin-Coated Liquid Crystal Film for Simple, Sensitive and Label-Free Protein Detection

“…We have demonstrated that s nal amplification can be achieved with both spin-coated film and sandwiched cell of LC-photopolymer composite [12,31]. In addition, the intensity of the optical response Signal amplification mediated by labeling with gold nanoparticles has been reported in several LC-based biosensors [33][34][35][36][37]. To eliminate the costly and time-consuming procedure of labeling, a number of label-free approaches aimed at enhancing the optical signal and thereby improving detection sensitivity at the LC-solid interface of a sandwiched LC cell were proposed, which include the use of a highly birefringent LC [38,39] and LCphotopolymer composite [12], adjustment of the direction of linearly polarized light for a dye-doped LC [16], modification of the alignment layer by ultraviolet light irradiation [40], and application of a weak electric field to orient LC molecules in a pre-tilted state [41].…”

“…Taking advantage of spin-coating, LC fi thickness can be directly and easily reduced to a desired smaller value (<5 μm) to enhan the optical response. Signal amplification mediated by labeling with gold nanoparticles has been repor in several LC-based biosensors [33][34][35][36][37]. To eliminate the costly and time-consuming p cedure of labeling, a number of label-free approaches aimed at enhancing the optical s nal and thereby improving detection sensitivity at the LC-solid interface of a sandwich LC cell were proposed, which include the use of a highly birefringent LC [38,39] and L photopolymer composite [12], adjustment of the direction of linearly polarized light fo dye-doped LC [16], modification of the alignment layer by ultraviolet light irradiation [ and application of a weak electric field to orient LC molecules in a pre-tilted state [4 Because of the similar working principles between the LC film and LC cell in biodetecti at the LC-glass interface, most of the previously reported signal amplification approach for sandwiched cells would be applicable to the LC film.…”