A third-order mode high frequency biosensor with atomic resolution

• Published in: Biosensors & bioelectronics 2015-09, Vol.71, p.261-268
• Main Authors: Cai, Hua-Lin, Yang, Yi, Chen, Xiao, Mohammad, Mohammad Ali, Ye, Tian-Xiang, Guo, Cang-Ran, Yi, Li-Ting, Zhou, Chang-Jian, Liu, Jing, Ren, Tian-Ling
• Format: Article
• Language: English
• Subjects: 3T3 Cells; Acoustics - instrumentation; Animals; Atomic resolution; Base Sequence; Biosensing Techniques - instrumentation; Biosensors; Cancer cell; Cell Line, Tumor; Deoxyribonucleic acid; Devices; DNA; DNA - analysis; Equipment Design; High frequency; Label free; Limit of Detection; Medical; Medical devices; Mice; Niobium - chemistry; Oxides - chemistry; SAW biosensor; Sound; Surface acoustic waves; Transducers
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2015.04.043

An atomic resolution ultra-high sensitivity surface acoustic wave (SAW) biosensor for DNA sequences and cells detection is proposed. Interdigitated transducers (IDTs) fabricated on LiNbO3 substrate achieve a high quality factor (Q) of over 4000 at a frequency of 6.4GHz (third-order harmonic mode) using an optimized design and process. The biosensor shows excellent linear responses to target DNA in the range from 1μg/ml to 1ng/ml with a high sensitivity of 6.7×10−16g/cm2/Hz, hence the difference of a single hybridized DNA base can also be distinguished. With such a high mass resolution, the biosensor is capable of quantitative detection of living cancer cells. The frequency responses of single mouse mammary adenocarcinoma (EMT6) cell and mouse fibroblast (3T3) cell are studied. The interferences in the experiments show insignificant influence on the frequency shift, which verifies the high selectivity of the biosensor. The biosensor is also able to repeat the sensing ability after rough cleaning, therefore cost reduction is achieved from the recycling process in practical applications. The detection limit is defined from the noise analysis of the device, atomic resolution is realized according to the calculation, thereby initiating a potential tool for high-precision medical diagnoses and phenomena observation at the atomic-level. •A highly sensitive surface acoustic wave (SAW) based biosensor was developed.•A 6.4GHz resonant frequency with a quality factor exceeding 4000 was achieved.•The SAW biosensor was used to sense DNA, EMT6 cells, and 3T3 cells.•Excellent linearity to target DNA (1μg/ml to 1ng/ml) with a sensitivity of 6.7×10−16g/cm2/Hz.•The SAW biosensor could sense even a single DNA base or a single cell.