Dynamic layer-by-layer films on nanofiber membrane: a platform for ultra-sensitive bacterial concentration detection

Abstract

Herein, a new platform was established for ultra-sensitive bacterial concentration detection. The sensing system had a linear relationship with the logarithm of bacterial concentration from 1 × 101 to 1 × 105 CFU mL-1 within 5 min. Moreover, the platform showed excellent consistency compared with the traditional standard method against practical samples.

Surface Functional Nanofiber Membrane for Ultrasensitive and Naked-Eye Visualization of Bacterial Concentration

“…Bacteria induced the dissociation of the LBL film from the BDM surface when BDMs were immersed into bacterial suspensions. In our previous work, we had proved that the dissociation rate of LBL films showed positive correlation with the bacterial concentration . The obtained results showed that the fluorescence intensity of the BDM surface decreased linearly when the BDM was immersed in the bacterial suspension.…”

“…Compared with proteins and polymers, bacteria can preferentially bind to various ligand molecules because the half-electric layer on the bacterial surface is higher than those of proteins and polymers . Taking advantage of the nature of bacteria, we have proved that bacteria can induce an ultrathin film to dissociate by a zero-order kinetic mechanism within 5 min . The zero-order dynamic model (linear) is the best mode for an analytical method, so bacterium-responsive ultrathin films were ideal for rapid (minute-level) quantitative bacterial detection.…”

“…27 Taking advantage of the nature of bacteria, we have proved that bacteria can induce an ultrathin film to dissociate by a zeroorder kinetic mechanism within 5 min. 28 The zero-order dynamic model (linear) is the best mode for an analytical method, so bacterium-responsive ultrathin films were ideal for rapid (minute-level) quantitative bacterial detection. However, the work still had three defects: (1) it did not provide nakedeye visualization, so professional and equipment dependence could not be avoided, (2) the synthesis process of labeled fluorescent molecule (BODIPY) was complex, so the bacterial detection platform had high production cost, and (3) the effect of cationic polymers on the detection efficiency was not fully understood and studied.…”