Opt Express. 2024 Aug 26;32(18):31514-31524. doi: 10.1364/OE.533018.
A tapered thin-diameter photonic crystal fiber interferometer (TTD-PCFI) biosensor is proposed and demonstrated for DNA hybridization detection with an ultra-low limit of detection (LoD) and high specificity. The TTD-PCFI is fabricated by arc-discharged melting and adiabatic tapering, with a lower loss and stronger evanescent optical field. The fabricated TTD-PCFI with a diameter of 8.63 µm achieves a high refractive index sensitivity of 3842.5 nm/RIU. DNA hybridization detection of concentration ranging from 1 fM to 1 pM is achieved, with a sensitivity of 632 pm/lg(fM). The measured LoD is as low as 410 aM. Single-base mismatch detection of 25-base target single-stranded DNA is also achieved. The proposed label-free DNA biosensor has the advantages of the ultra-low LoD, high specificity, and real-time detection, which has great application prospects in the fields of disease diagnosis, microbial detection, and environmental science.
一种锥形细径光子晶体光纤干涉仪（TTD-PCFI）生物传感器被提出并演示用于 DNA 杂交检测，具有超低检测限（LoD）和高特异性。TTD-PCFI 通过电弧放电熔融和绝热锥形化制造，具有更低的损耗和更强的倏逝光场。制造的 TTD-PCFI 直径为 8.63 µm，实现了 3842.5 nm/RIU 的高折射率灵敏度。实现了浓度范围从 1 fM 到 1 pM 的 DNA 杂交检测，灵敏度为 632 pm/lg(fM)。测量的 LoD 低至 410 aM。还实现了 25 碱基目标单链 DNA 的单碱基错配检测。所提出的无标记 DNA 生物传感器具有超低 LoD、高特异性和实时检测的优点，在疾病诊断、微生物检测和环境科学等领域具有广阔的应用前景。
