A TiO2 nanotube array decorated by Ag nanoparticles for highly sensitive SERS determination and self-cleaning of vitamin B12

The Ag-deposited TiO2 nanotube arrays (TNTA/Ag) are prepared via the decoration of Ag nanoparticles (Ag NPs) on an anodized TiO2 nanotube. Descriptive physicochemical features of prepared probes were studied by XRD, FESEM, and RAMAN analyses to prove the successful construction of ordered TNTA and decoration of Ag NPs over them. A highly appropriate and efficient determination method based on surface-enhanced Raman spec-troscopy (SERS) has been developed using TNTA/Ag probe for vitamin B12 detection. The results displayed that the TNTA/Ag probe has superior detection sensitivity with detection limit of as low as 2.48 x 10(-8) M and high reproducibility of different spots on the probe surface with a relative standard deviation of 9.69 %. Moreover, the prepared probe could clean itself due to the photocatalytic ability of TiO2 and surface plasmon resonance effect (SPR) of Ag NPs to be repeatedly used as a SERS probe. The reliability of TNTA/Ag SERS probe was affirmed further by the detection of vitamin B12 in real pharmaceutical samples.