This study aimed to investigate the effects of variations in precursor concentration (TiCl 3 solution) on the structural, morphological, and optical properties of rutile titanium dioxide (TiO 2 ) nanorods and fabricated metal–semiconductor–metal UV detector depending on the optimal sample. The nanorods were prepared from an aqueous solution of titanium (III) chloride (TiCl 3 ) on p-type, (111)-oriented Si substrates at different concentrations of TiCl 3 solutions (2, 3, 4, and 5mM). The experimental results showed that the TiO 2 nanorods grown at 4mM concentration exhibited optimal structural properties. A fast-response metal–semiconductor–metal UV detector was fabricated by depositing Pt contacts on the front of the optimal sample via RF reactive magnetron sputtering. Upon exposure to 365nm light (2.3mW/cm 2 ) at 5V bias voltage, the device showed 44.4 sensitivity. In addition, the internal gain was 1.45, and the photoresponse peak was 70mA/W. The response and the recovery times were calculated to be 7.8ms upon illumination to a pulse UV light (365 nm) at 5V bias voltage.