Label-free bacterial detection using polydiacetylene liposomes

Abstract

Polydiacetylene (PDA) liposomes were prepared to selectively capture target released from bacteria. Specific interplay between released-surfactin and PDA resulted in a conformal change in the structure of PDA, highlighting the potential of indirect interactions between bacteria and PDA in the construction of new label-free bacterial sensors.

Immobilized Polydiacetylene Lipid Vesicles on Polydimethylsiloxane Micropillars as a Surfactin-Based Label-Free Bacterial Sensor Platform

“…The high selectivity of amine functionalized PDA solutions toward surfactin has been reported in a number of works (Deleu et al, 2003;Bouffioux et al, 2007;Park et al, 2016). The interaction of amine functionalized PDA has been tested with various targets including the various surfactants (anion and cation), simple anions, and fatty acids.…”

“…Polydiacetylene (PDA)-based sensor as label-free bacteria detection has been intensively investigated due to its unique stimulus-induced significant color-changing properties from brilliant blue to red (Silbert et al, 2006;Scindia et al, 2007;Meir et al, 2008;Lee et al, 2016;Park et al, 2016). The fact that such a visible color change occurs in response to a variety of environmental perturbations including temperature, heat, mechanical stress, pH, and solvents lead to a nonspecific colorimetric response.…”

“…The fact that such a visible color change occurs in response to a variety of environmental perturbations including temperature, heat, mechanical stress, pH, and solvents lead to a nonspecific colorimetric response. Therefore, specifically designed ligands have been introduced as the terminal group of PDA for detecting specific types of bacterial strains with high sensitivity, such as glycine terminated PDA for colorimetric signaling of bacterial pore-forming toxin (Ma and Cheng, 2005), peptide functionalized PDA for detecting bacterial lipopolysaccharide (Wu et al, 2011), aptamer-based PDA for Escherichia coli O157:H7 detection (Wu et al, 2012), amine functionalized PDA for detecting surfactin from B. subtilis NCIB3610 (Park et al, 2016) and a Eu III -EDTA functionalized PDA for recognizing calcium dipicolinate (DPA), a major component of Bacillus anthrax endospores (Seo et al, 2017). However, the majority of the PDA-based sensors that have been reported were prepared in the form of a liposome in aqueous solution or thin film as two dimensional (2D) structures (Silbert et al, 2006;Scindia et al, 2007;Meir et al, 2008;Pires et al, 2011;Park et al, 2016;Seo et al, 2017).…”

“…The simple anions, short-chain fatty acids, and cation surfactants did not trigger colorimetric changes in PDA liposomes. Considering the pK b values of the terminal amine group on the PDA, it is expected that ammonium cation and electrostatic interaction with the negative charges of surfactin occurs (Park et al, 2016). Furthermore, the fatty acid chain of surfactin also can enhance the binding affinity with carbon backbones in PDA by van der Waals interaction and due to its amphiphilic nature, it can penetrate into the charged bilayer.…”

“…Furthermore, the fatty acid chain of surfactin also can enhance the binding affinity with carbon backbones in PDA by van der Waals interaction and due to its amphiphilic nature, it can penetrate into the charged bilayer. (Hupfer et al, 1983;Deleu et al, 2003;Bouffioux et al, 2007;Park et al, 2016).…”