Fig. 2: Plasmonic tweezers as actuators for selective trapping and enrichment of biological samples: DNAs, RNAs, proteins, exosomes, viruses, and pathogens.
From: Plasmonic biosensors and actuators for integrated point-of-care diagnostics
a Reversible trapping of lambda DNA on a metallic nanostructure by switching femtosecond-pulsed NIR laser irradiation on and off. Reprinted with permission from ref. 51. Copyright 2013 American Chemical Society. b The nanogap of a gold bowtie can create intense optical hot spots that trap DNA translocation through its nanopore, offering physical control over the speed of DNA movement. Reprinted with permission from ref. 54. Copyright 2015 American Chemical Society. c Plasmonic bacteria are forced to align on the nanopore. Reprinted with permission from ref. 285. Copyright 2018 Springer Nature. d An electrothermoplasmonic effect-based LSPR microfluidic sensing chip can overcome optoelectrical convection flow, demonstrated through high fluid velocities and improved immunoglobulin G detection performance. Reprinted with permission from ref. 61. Copyright 2018 American Chemical Society. e Thermophoretic force is created when photothermal heating around gold nanorods under resonant laser irradiation (785 nm) drives convection flow, enabling the localized plasmonic gold nanorods assembly with micro-sized bacteria without requiring specific linkers or templates. Reprinted with permission from ref. 70. Copyright 2022 Wiley-VCH GmbH. f Nanocavities of geometry-induced electrohydrodynamic tweezers (GET) allow a.c. electro-osmotic flow at the center of the void region where individual EVs are to be trapped, enabling plasmon-enhanced optical trapping under laser illumination without causing harmful heating effects. Reprinted with permission from ref. 62. Copyright 2023 Spinger Nature.
