Construction of nanoantennas on the bacterial outer membrane

Abstract

We demonstrate a simple manipulation of gold nanoparticles that creates a structure-dependent nanometer-scale antenna on the surface of bacteria. Our studies illuminate the concept of the "effective use of light" based on the absorption and emission of light by antennas formed on bacteria.

Light-scattering Characteristics of Metal Nanoparticles on a Single Bacterial Cell

“…In contrast, almost all of the negatively charged Au NPs were observed on the substrate instead of the bacterial surface, indicating that the electrostatic force dominated the interaction between the Au NPs and the bacterium. 18 A dark-field microscopic observation was carried out to evaluate the light-scattering characteristics of the Au NPs adsorbed on a bacterium, as shown in Fig. 4B.…”

“…16 Gram-negative bacteria possess a negatively charged surface (-40 --20 mV) when dispersed in a wide range of pH. 17,18 This suggests that the negative charge is pre-dominant on the surface of a bacterium due to phosphate and carboxylate groups compared with amino groups which are included in LPS. 19 To achieve accurate cell imaging, it is necessary to design the NPs in terms of the sensitivity and selectivity.…”

Investigation Concerning the Formation Process of Gold Nanoparticles by Shewanella oneidensis MR-1

“…Sodium formate (0.10 M) and tetrachloroauric(III) acid (2.0 mM) were added to the bacterial suspension (20 mL), which was then incubated under a nitrogen-saturated atmosphere at 25 C for 24 h. The color of the suspension changed from light yellow (tetrachloroauric acid color) to light red purple over a period of 3 h, and gradually became dark reddish-purple because of a localized surface plasmon resonance (LPSR) of the Au NPs. 17,18 In accordance with the color change, the UV-vis spectra revealed no peaks at the early stage of incubation; however, a peak at approximately 550 nm gradually became intense, as shown in Fig. 1A.…”

Direct Imaging of Carboxymethyl Cellulose-mediated Aggregation of Lactic Acid Bacteria Using Dark-field Microscopy

“…Thus, DFM imaging with a good contrast enables us to visualize metal nanoparticles, [18][19][20][21][22] such as Au or Ag, and to measure the bacterial motion and high-speed rotation of bacteria flagella. [23][24][25][26][27] Since DFM images obtained in this study also showed good contrast, we tried to analyze timedepended changes of the aggregate sizes of LAB mediated by CMC.…”