Off-Resonance SERS Nanoprobe-Targeted Screen of Biomarkers for Antigens Recognition of Bladder Normal and Aggressive Cancer Cells.

The discovery of different binding receptors to allow rapid and high-sensitivity detection via a noninvasive urine test has become the goal for urothelial carcinoma (UC) diagnosis and surveillance. In this study, we developed a new screening membrane receptor platform for bladder cancer cells by integrating surface-enhanced Raman spectroscopy (SERS) with 4-aminothiophenol (4-ATP)-modified AuAg nanohollows upon NIR laser excitation. AuAg nanohollows have an absorption band at ∼630 nm, and slightly off-resonance 785 nm laser excitation is used for minimal photothermal effect. Using the same carbodiimide cross-linker chemistry to conjugate anti-EGFR, transferrin (TF), 4-carboxyphenylboronic acid (CPBA), folic acid (FA), and hyaluronic acid (HA) molecules, by screening the 4-ATP SERS signals intensity, we demonstrated that the targeting efficiency with the cost-effective CPBA molecule is comparable with the conjugation of anti-EGFR antibody to aggressive T24 cancer cells (high-grade), while weak intensity 4-ATP SERS responses to targets were obtained by grade-I RT4 bladder cancer cells, NIH/3T3 fibroblast cells, and SV-HUC1 bladder normal cells. This SERS nanoprobe platform makes primary bladder carcinoma screening from in vitro to ex vivo more straightforward. Our demonstration offers exciting potential for SERS screening of specific receptors on cancer cells of different grades and facilitates new opportunities ranging from surface engineering of SERS material tags to SERS imaging-guided and targeted phototherapy of cancer cells by controlling the laser powers.

Developing Rapid Antimicrobial Susceptibility Testing for Motile/Non-Motile Bacteria Treated with Antibiotics Covering Five Bactericidal Mechanisms on the Basis of Bead-Based Optical Diffusometry.

Rapid antimicrobial susceptibility testing (AST) is an effective measure in the treatment of infections and the prevention of bacterial drug resistance. However, diverse antibiotic types and bacterial characteristics have formed complicated barriers to rapid diagnosis. To counteract these limitations, we investigated the interactions between antibiotic-treated bacteria and functionalized microbeads in optical diffusometry. The conjugation with bacteria increased the effective microbead complex size, thereby resulting in a temporal diffusivity change. The yielded data were sorted and analyzed to delineate a pattern for the prediction of antimicrobial susceptibility. The outcome showed that a completed rapid AST based on the trend of microbead diffusivity could provide results within 3 h (2 h measurement + 1 h computation). In this research, we studied four bacterial strains, including Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus, and six antibiotics. Despite the different inhibitory effects caused by various antibiotics, similar trends in diffusivity alteration for all susceptible and resistant cases in the last 40 min of the 2-h measurement period were deduced. In addition, the AST results obtained using optical diffusometry showed good agreement with those acquired from the commercial instrument and conventional culture methods. Finally, we conducted a single-blinded clinical test, and the sensitivity, specificity, and accuracy of the system reached 92.9%, 91.4%, and 91.8%, respectively. Overall, the developed optical diffusometry showcased rapid AST with a small sample volume (20 µL) and low initial bacterial count (105 CFU/mL). This technique provided a promising way to achieve early therapy against microbial diseases in the future.