Diatom Frustule Array for Flow-Through Enhancement of Fluorescent Signal in a Microfluidic Chip

Abstract

Diatom frustules are a type of natural biomaterials that feature regular shape and intricate hierarchical micro/nano structures. They have shown excellent performance in biosensing, yet few studies have been performed on flow-through detection. In this study, diatom frustules were patterned into step-through holes and bonded with silicon substrate to form an open-ended filtration array. Then they were fixed into a microfluidic chip with a smartphone-based POCT. Human IgG and FITC-labeled goat–anti-human IgG were adopted to investigate the adsorption enhancement when analyte flowed through diatom frustules. The results indicated up to 16-fold enhancement of fluorescent signal sensitivity for the flow-through mode compared with flow-over mode, at a low concentration of 10.0 μg/mL. Moreover, the maximum flow rate reached 2.0 μL/s, which resulted in a significant decrease in the testing time in POCT. The adsorption simulation results of diatom array embedded in the microchannel shows good agreement with experimental results, which further proves the filtration enrichment effect of the diatom array. The methods put forward in this study may open a new window for the application of diatom frustules in biosensing platforms.

Micro/Nanofabrication, Assembly, and Actuation Based on Microorganisms: Recent Advances and Perspectives

“…Reproduced with permission. [ 275 ] Copyright 2021, MDPI (Basel, Switzerland). d) Spirulina and the corresponding Ag microcoils.…”

“…Copyright 2019, Elsevier. Reproduced with permission [275]. Copyright 2021, MDPI (Basel, Switzerland).…”

Limit-Defying μ-Total Analysis System: Achieving Part-Per-Quadrillion Sensitivity on a Hierarchical Optofluidic SERS Sensor

“…Convection flow establishes analyte movement from regions of high to low density, leading to translational local accumulation of the analyte in DE cavities. ,,, This device-directed analyte accumulation is further improved or supported by the biochemical and porous nature of our choice of substrate material i.e., DE. Because of their biological origin, the DE surface is rich in anionic silanol groups that bestow them with hydrophilic characteristics, helping in drawing and retaining more test fluid in the cavities. − However, the porosity in DE increases the specific surface area by introducing multiple interaction sites in the exposed cavity walls, contributing to a high analyte flux at any time. − The device-directed analyte accumulation is further complemented by the improved Raman scattering due to the silver-functionalized DE lining the final level of the sensing device. Compared to DE or silver nanoparticles alone, the optical potential of plasmonic-functionalized DE to tune Raman scattering is much superior.…”

Analysis on Component of Cultured Diatoms and Their Application as Li‐Ion Battery Anodes

“…This kind of creature is composed of cell wall (diatom frustule made of amorphous SiO 2 ) and intracellular organic matter (e. g., protein, lipid, nucleic acid, chlorophyll), which are endowed with hierarchically ordered porous structure and outstanding biocompatibility [1–4] . Based on its unique structures and natural biological features, diatoms are widely researched for applications in various fields such as biomedicine, optoelectronics, transducers, and batteries [5–11] …”

“…[1][2][3][4] Based on its unique structures and natural biological features, diatoms are widely researched for applications in various fields such as biomedicine, optoelectronics, transducers, and batteries. [5][6][7][8][9][10][11] To construct anodes for LIBs, various researches have been conducted to apply silicon dioxide materials, [12][13][14][15] and it is also verified that element doping of mesoporous silica (e. g., carbon) can lead to performance enhancement. [16][17][18][19][20][21] Thereon, diatoms have attracted much attention to fabricate anodes for LIBs in recent years.…”