Unlike antibiotic residue detection, the sample pre-treatment of incubation at high temperature is not suitable for evaluating the sensitivity of pathogenic microorganisms to antibiotics. Nonetheless, after bacterial phenotypic identification, the samples can be diluted with a detection buffer to reduce matrix interference. For example, the samples were centrifuged at 2 000×
g for 10 min to remove the blood corpuscles, and the resulting supernatant and bacterial pellet were homogenized and then diluted 30 000 times with the broth
[20]. Urine specimens with pathogenic bacteria were diluted with trypticase soy broth and were introduced into the detection system by Ivančić et al.
[21]. Above all, these evaluation experiments of pathogenic microorganisms’ sensitivity to antibiotics need bacterial phenotypic identification, which is more complex to operate and time-consuming. The introduction of receptors and magnetic nanoparticles promotes the sample pre-treatment efficiency. The target bacteria can be captured by specific receptors, and quickly separated by magnetic nanoprobes with external magnets, which can not only reduce matrix interferents futher, but also perform bacterial phenotypic identification. For example, the urinary tract infections pathogen species in an artificial urine samples with capture antibodies immobilized on the carrier, which was then quantified
via an ATP bioluminescence assay and given personalized antibiotic therapy
[22]. However, antibodies are complicated to prepare, high-cost, and susceptible to harsh environments (e.g., pH, temperature, organic reagents). Nonetheless, aptamers are easy to synthesize, stable to preserve for a long time, and have a wider range of potential targets. For example, Wang et al. developed a hand-held agitator array modified with hyperbranched aptamer probes for the specific adsorption extraction of
Salmonella typhimurium in complex water samples
[23]. However, the aptamers require long incubation times with analytical targets. Moreover, the conformation of aptamers is inconstant, and thus the target capture rate is variable. Compared to antibodies and aptamers, phages can be produced on a large scale easily and inexpensively in most microbiology laboratories. Furthermore, phages can distinguish between live and dead bacteria. An ATP bioluminescence assay was developed with phage-functionalized magnetic beads for rapid and sensitive detection of
Vibrio parahaemolyticus in aquatic products by Du et al.
[24]. The
Vibrio parahaemolyticus were captured and enriched by phage VPHZ6 coupled to a magnetic bead, which shortened detection time and improved method sensitivity
[24]. Furthermore, Li et al. developed a similar ATP bioluminescence assay for
Staphylococcus aureus detection
[25]. The phage-functionalized magnetic beads brought a tenfold increase in sensitivity during detection in skim milk and chicken samples, with high recoveries of
Staphylococcus aureus in samples
[25]. However, the phages are susceptible to harsh environments (pH, temperature, organic reagents). Above all, these specific receptors (antibody, aptamer, phages) have great potential but some shortcomings. Therefore, in future studies, the sensitivity and specificity of these specific receptors should be further improved.