拉曼散射自1928年被諾貝爾獎得主錢德拉塞卡拉-拉曼(Chandrasekhara V. Raman)博士發現後,己經被廣泛地利用來測量各種分子與物質的振動光譜,並藉此來研究分子的結構與物質的組成。但它有一個很大的限制就是拉曼光譜訊號非常微弱,要取得一個樣品的拉曼光譜常常曠日費時。本團隊利用緊密且有序排列的「奈米貴金屬(銀或金)粒子陣列」(當作拉曼放大器)來大幅地增強吸附在其表面上分子的拉曼光譜訊號,即所謂的表面增強拉曼光譜(surface-enhanced Raman spectroscopy, SERS)。加上這種材料的高再現性與均勻度,大大的改變了拉曼光譜技術在化學與生物科技的實用性。我們也積極開發第二代具有捕捉及偵測雙功能的生物檢測晶片,在原有的「奈米貴金屬陣列」上披覆一層胜肽醣-「萬古黴素(vancomycin)」,藉由「萬古黴素」可以快速捕捉病菌(但不會捕捉血液中的血球細胞),再利用拉曼光譜技術作快速檢測。其最大優勢在於其不需經過螢光染色及生物培養(label-and culture-free),可在極短的時間內來快速篩檢病菌,另外此雙功能晶片也兼具檢測「抗藥型病菌」的功效。此種創新的工具讓我們在發展快速菌種鑑定與細菌對抗藥性反應監測上獲得了許多的成果,利用光學的即時反應偵測特性,跳脫傳統的生物培養檢測,使我們面對未知的細菌能有更快速的了解,在治療和預防上節省寶貴的時間,也給醫療檢驗單位開創另一個病菌檢測方向。
Since the discovery of Raman scattering by Nobel laureate Chandrasekhara V. Raman in 1928, it has been used to measure vibrational spectra of numerous molecules and to study the structures of molecules and compositions of materials. However, the weak signal of Raman scattering has limited the scope of its applications. We have used highly ordered arrays of closely packed metal (silver or gold) nanoparticles used to enhance the Raman spectral signals of the molecular adsorbed on the surface. This latest development in the so-called surface-enhanced Raman spectroscopy (SERS) greatly increased the possibility of its practical applications in the chemical and biological analysis because of the high reproducibility and uniformity of such SERS substrates. Furthermore, we also demonstrated a dual-function biochip that is not only able to capture bacteria effectively in human blood but also enhances the Raman signals of the bacteria, allowing for their analysis by SERS. The core of the biochip is an array of Ag nanoparticles coated by vancomycin, on which bacteria are selectively captured while blood cells are excluded. Our results represent a critical step towards the creation of SERS-based multifunctional biochips for rapid culture- and label-free detection and drug-resistant testing of microorganisms in clinical samples.