The invention discloses an SERS-SPR dual-mode sensor for
nucleic acid detection. The SERS-SPR dual-mode sensor comprises a detection
chip and
a DNA probe, wherein the detection
chip is a silver
nanopore-
nanorod array substrate of which the surface is modified with tetrahedral
DNA. The invention further discloses a preparation method and a detection method of the SERS-SPR dual-mode sensor. The detection method comprises the following steps of: sequentially mixing the detection
chip with a to-be-detected liquid sample and
a DNA probe solution; forming a 'detection chip-target
DNA-
DNA probe' compound through complementary
pairing; and then sequentially carrying out a transmission spectrum test and an SERS test. According to the detection method, high-sensitivity and specific dual-mode sensingdetection on
nucleic acid in serum is realized through
wavelength change of characteristic valleys of a transmission spectrum, an SERS spectrum and characteristic
signal intensity values of the SERSspectrum, the detection limits of the SERS sensing mode and the SPR sensing mode reach the sub-femtomole per
liter magnitude and the sub-picomole per
liter magnitude respectively, and the nucleic acidmarker can be detected in complex environments such as serum.