Quantum Dots for Pathogenic Bacterial Monitoring and Combating

Abstract

including neonatal meningitis, [6] diarrhoea, [7] infected cutaneous wound [8] or bloodstream diseases, [9][10][11] etc. Antibiotic treatment strategies against these bacteria have been widely applied while antimicrobial resistance has been arousing gradually. [12][13][14][15][16][17] What is worse, the biofilmrelated infection has been a tough issue for bacterial infectious treatment since it is usually chronic and much harder to eradicate. [18][19][20] Therefore, effective antibacterial treatments for drug-resistant pathogenic bacteria are vital problems for clinical therapy. [21] Some anti-microbial trials were carried out like phages, bacteriocins, and antimicrobial peptides [22] along with various therapeutic methods. [23][24][25] Among them, nanomaterials are considered as compatible solutions [23,26] due to their facile synthesis methods and rich-sourced precursors, broad-spectrum sterilization, and low drug resistance. [27][28][29][30][31] Nanomaterials are generally easy to be modified or doped to enhance the affinity toward bacteria for the sake of combating or drug delivery. [32][33][34][35] The antibacterial mechanism [36,37] could be result from the sharp edges-based physical cutting, [38,39] photothermal effects, [40][41][42] and photo dynamic or chemical dynamic properties, that could produce reactive oxygen species (ROS).Pathogenic bacteria monitoring mainly conducted by culturing them in agar-based media, and subsequently testing them with biochemical probes. [43][44][45][46] Although this conventional method enables clinical diagnoses with relatively reliable outcomes, the long culturing time renders the "golden therapeutical window" for patients. So more rapid and accurate detecting technologies have been invented. One of the most evolutionary methods is the polymerase chain reaction, [47][48][49] which can identify the bacterial classification and provide gene expression level in a few hours with better accuracy. [47,50] Besides, the coupling of chromatography and mass spectra like matrix-assisted laser desorption ionization time-of-flight mass spectrometry [51][52][53][54][55] can play a more exact role in diagnosis. [56] Though these advanced instrumental-relied methods can lead to fast diagnostic, the expensive apparatus, environmentally unfriendly reagents, [57] professional sites and technical personnel requirements limited their utilization in real-time monitoring and point-of-care sensing. By contrast, easy and fast monitoring methods for the pathogen, such as electrochemical and fluorescence sensors, were brought out as powerful supplements. [58][59][60][61][62] Therein, Antibiotic resistance and pathogenic bacterial monitoring are two main challenges in clinical diagnostics and treatment of bacteria. To conquer those issues, many new materials and novel technologies are explored. Among them, quantum dots (QDs) are regarded as not only powerful bacteriostatic agents, but also bacterial monitoring probes due to their excellent photoluminescence properties, tunable multiwavelength lumine...