Biomimetic Ag/ZnO@PDMS Hybrid Nanorod Array-Mediated Photo-induced Enhanced Raman Spectroscopy Sensor for Quantitative and Visualized Analysis of Microplastics

Authors：Zhu, Zhengdong; Han, Konghao; Feng, Yating; Li, Zhihao; Zhang, Anxin; Wang, Tao; Zhang, Maofeng^*; Zhang, Wei^*

Source：ACS applied materials & interfaces, 2023, 15(30): 36988-36998.

DOI：10.1021/acsami.3c06024

• photo-induced enhanced Raman spectroscopy (PIERS)
• biomimeticsynthesis
• dragonfly wings
• microplastics
• visualized detection
• quantitative detection

Microplastics are persistent pollutants that accumulatein theenvironment and can cause serious toxicity to mammals. At present,few technologies are able to quantitatively detect chemicals and providemorphological information simultaneously. Herein, we developed a dragonfly-wing-mimickingZnO nanorod array decorated with AgNPs on polydimethylsiloxane (PDMS)as a surface-enhanced Raman spectroscopy (SERS) and photo-inducedenhanced Raman spectroscopy (PIERS) substrate for trace analysis ofmicroplastics. The Ag/ZnO@PDMS hybrid nanorod array endows the sensorwith high sensitivity and signal repeatability (RSD & SIM; 5.89%),ensuring the reliable quantitative analysis of microplastics. Importantly,when the noble metal-semiconductor substrate was pre-radiatedwith ultraviolet light, a surprising PIERS was attained, achievingan additional enhancement of 11.3-fold higher than the normal SERSsignal. By combining the PIERS technology with the "coffeering effect", the sensor successfully discerned microplasticsof polyethylene (PE) and polystyrene (PS) at a trace level of 25 & mu;g/mLeven with a portable Raman device. It was capable of identifying PSmicrospheres in contaminated tap water, lake water, river water, andseawater with detection limits of 25, 28, 35, and 60 & mu;g/mL,respectively. The recovery rates of PS microspheres in four waterenvironments ranged from 94.8 to 102.4%, with the RSD ranging from2.40 to 6.81%. Moreover, quantitative and visualized detection ofmicroplastics was readily realized by our sensor. This portable PIERSsensor represents a significant step toward the generalizability andpracticality of quantitative and visual sensing technology.