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Previous studies regarding the associations between perfluoroalkyl and polyfluoroalkyl substances (PFAS) and autism spectrum disorder (ASD) have yielded inconsistent results, with the underlying mechanisms remaining unknown. In this study, we quantified 13 PFAS in cord serum samples from 396 neonates and followed the children at age 4 to assess ASD-related symptoms. Our findings revealed associations between certain PFAS and ASD-related symptoms, with a doubling of perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA) concentrations associated with respective increases of 1.79, 1.62, and 1.45 units in language-related symptoms and PFDA exhibiting an association with higher score of sensory stimuli. Nonlinear associations were observed in the associations of 6:2 chlorinated polyfluorinated ether sulfonate (Cl-PFAES) and 8:2 Cl-PFAES with ASD-related symptoms. Employing weighted quantile sum (WQS) regression, we observed significant mixture effects of multiple PFAS on all domains of ASD-related symptoms, with PFNA emerging as the most substantial contributor. Assuming causality, we found that 39–40% of the estimated effect of long-chain PFAS (PFUnDA and PFDoDA) exposure on sensory stimuli was mediated by androstenedione. This study provides novel epidemiological data about prenatal PFAS mixture exposure and ASD-related symptoms.

Here we report a novel method for detecting 3,4-dihydroxyphenylalanine (l-DOPA) and tyrosinase (TR) activity based on surface-enhance Raman scattering (SERS) by employing a large-scale versatile three-dimensionally (3D) ordered nanocomposite (SiO2/GNPs) array as a nanosensor. l-DOPA could reduce AuCl4−to Au0and enlarge the gold nanoparticles (GNPs) that attach on the surface of the SiO2/GNPs array, the preadsorbed GNPs serve as nucleation sites for Au0to deposit. As the concentration of l-DOPA increases, the surface coverage of resultant Au0on silica cores increases accordingly until complete gold nanoshells (GNSs) are formed. During the growth procedure, the SERS-activity of the GNSs arrays correlate well with the concentration of l-DOPA, which indicates that this SiO2/GNPs array is a potential nanosensor for detecting l-DOPA. As TR can catalyze the hydroxylation of l-tyrosine to form l-DOPA, this approach can also be employed to analyze the activity of TR, which possesses vast clinical and food industrial importance. Compounds such as cinnamic acid and p-hydroxybenzoic acid can inhibit the TR activity. Thus, the TR-triggered growth of the GNSs array system can also be used to detect the TR inhibited activity of inhibitors.