Ultrasensitive Detection Using Surface Enhanced Raman Scattering from Silver Nanowire Arrays in Anodic Alumina Membranes

Periodical arrays of silver nanowires about 60 nm in diameter were assembled in anodic alumina membranes by electrochemical deposition. After a partial removal of the membrane, the as-grown arrays were used as a surface enhanced Raman scattering substrate. Raman spectra of Rhodamine 6G solutions with different concentrations (10(-6) M, 10(-9) M, 10(-12) M and 10(-13) M) were measured on such substrates. According to a series of measurements, it is found that the Raman signals of the probe solution with a Rhodamine 6G concentration of 10-13 M can still be detected with a visible light (514.5 nm) excitation. The high detection sensitivity is seldom reported by other silver substrates. Further improvements may be achieved by adjusting the parameters (period, diameter and aspect ratio) of the nanowire arrays. Compared to other substrates, as-fabricated substrates are easy to fabricate, low in cost, flexible to adjust and convenient in measurement. Such substrates may have great potential in the detection of Persistent Organic Pollutants.