Performance of wild, tailed, humidity-robust phage on a surface-scanning magnetoelastic biosensor for Salmonella Typhimurium detection

[Display omitted] •The performance of a tailed phage was firstly compared with a filamentous phage.•Tailed phage showed excellent binding interaction with a positively charged sensor.•Tailed phage exhibited a competitive humidity-robustness and specificity.•Detection limit and sensitivity of tailed phage were greater than filamentous phage.•Tailed phage demonstrated reliable detection performance at ambient humidity. A wild, tailed phage (TST) was compared with a genetically modified, filamentous phage (FST) for S. Typhimurium (ST) detection. When both phages were introduced into oppositely charged MUA and MUAM sensors, the RU values of TST showed an obvious increase on the MUAM sensor. The sensitivity of TST [54.78 ΔRU/(log PFU/mL)] was greater than that of FST [48.05 ΔRU/(log PFU/mL)]. The binding affinity (KD = 1.75 × 10−13 M) of TST on MUAM sensor was greater than that of FST. Both phages were specific to only ST, and TST exhibited a persistent binding capability at 50 % RH. When each phage-immobilized sensor was employed on chili pepper, the sensitivity [880.80 Hz/(log CFU/mL)] and detection limit (1.31 ± 0.27 log CFU/mL) of TST were significantly greater than those of FST. The orientation of TST on sensor promoted the uniform capture of bacteria and enhanced the reliable performance of a surface-scanning magnetoelastic biosensor.