Fluorescent nanodiamond‐bacteriophage conjugates maintain host specificity

Abstract

Rapid identification of specific bacterial strains within clinical, environmental, and food samples can facilitate the prevention and treatment of disease. Fluorescent nanodiamonds (FNDs) are being developed as biomarkers in biology and medicine, due to their excellent imaging properties, ability to accept surface modifications, and lack of toxicity. Bacteriophages, the viruses of bacteria, can have exquisite specificity for certain hosts. We propose to exploit the properties of FNDs and phages to develop phages conjugated with FNDs as long-lived fluorescent diagnostic reagents. In this study, we develop a simple procedure to create such fluorescent probes by functionalizing the FNDs and phages with streptavidin and biotin, respectively. We find that the FND-phage conjugates retain the favorable characteristics of the individual components and can discern their proper host within a mixture. This technology may be further explored using different phage/bacteria systems, different FND color centers and alternate chemical labeling schemes for additional means of bacterial identification and new single-cell/virus studies.

Recent Advances in the Applications of Carbon Nanostructures on Optical Sensing of Emerging Aquatic Pollutants

“…In another interesting work, the fluorescent NDs conjugated with bacteriophage viruses to detect E. coli suspended in aqueous buffer. [70] The ND-phage conjugate demonstrated stable fluorescence and recognized different strains of E. coli, owning to the exceptional selectivity of the bacteriophages as shown in Figure 5. The bright and distinct Raman signature of NDs at 1332 cm À 1 is another intriguing property, making them attractive Raman reporter tags.…”

“…Interestingly, the functionalized NDs (80 μg mL −1 ) can efficiently remove bacterial contamination (> 1000 mg mL −1 ) in the presence of a 10 μm pore‐size commercial filter. In another interesting work, the fluorescent NDs were conjugated with bacteriophage viruses to detect E. coli suspended in aqueous buffer [70] . The ND‐phage conjugate demonstrated stable fluorescence and recognized different strains of E. coli , owning to the exceptional selectivity of the bacteriophages as shown in Figure 5.…”

Nanomaterials for virus sensing and tracking

“…Therefore, no binding between the conjugates and non-target bacteria (yellow) was observed. 184 In this case, it is essential to optimize the FND:phage ratio as free streptavidin FNDs as well as unbound biotinylated phages can result in errors such as false positives or inaccurate visualization. Additional washing steps also help alleviate false-positive results.…”

Advances in the Development of Phage-Based Probes for Detection of Bio-Species

“…Owing to the high throughput and effectiveness of this technique, many scholars have studied and developed a variety of phage display technologies. M13, T4, T7, and λ phage display systems are currently the most commonly used [ 9 , 10 , 11 , 12 ]. A phage that displays a fluorescent protein or luciferase and specifically binds to its host bacteria is similar to fluorescently labeled antibodies.…”