SERS nanotags for ultrasensitive and dual biomarker detection of breast cancer

• A new SERS-based biosensor has been developed for ultrasensitive detection of breast cancer biomarkers. • The detection limit of this method of BRCA1 and BRCA2 were as low as 0.61 and 0.78 pM, respectively. • Dual detection of BRCA1/2 genes is achieved in cell lysates. Sensitive and simultaneous detection of breast cancer 1 (BRCA1) and breast cancer 2 (BRCA2) is of significance for the early diagnosis of breast cancers, but it still challenges conventional methods. Herein, we developed a novel surface-enhanced Raman spectroscopy (SERS) based method for quantification of breast cancer biomarkers BRCA1 and BRCA2. Highly uniform SERS-active substrate is obtained by self-assembly of silver nanoparticles on a polystyrene template. Gold core silver shell (Au@Ag) nanoparticles embedded with Raman probes were synthesized and used as SERS nanotags. The target genes BRCA1 and BRCA2 were detected through the capture DNA modified on the Ag chip and the probe DNA attached on the SERS nanotags. Dual detection is achieved by changing Raman probes, capture DNA and probe DNA sequences. This method exhibits high selectivity and sensitivity with a wide dynamic linear range (0.001−1000 nM). Moreover, its applicability to the detection of BRCA1 and BRCA2 in cell lysates has been proved, showing its potential application in breast cancer diagnosis and prognosis.