A Versatile SERS Sensor for Multiple Determinations of Polycyclic Aromatic Hydrocarbons and Its Application Potential in Analysis of Fried Foods

Abstract

Polycyclic aromatic hydrocarbons (PAHs), due to their high hydrophobicity, have low affinity for metallic SERS-active surfaces, which leads to their low SERS detection sensitivity. Various functional groups have been used to improve the affinity of metallic substrates towards the target PAHs. However, a large portion of the signals generated from the “first-layer effect” of the functionalized substrates may complicate the spectrum, leading to a distortion in the assignment of the intrinsic SERS fingerprints of PAHs. In this study, a SERS sensor composed of Au nanoparticles (AuNPs) and reoxidized graphene oxide (rGO) was developed for the simultaneous determination of 16 EPA priority PAHs. The synthesis of the rGO/AuNP substrate can be realized without a complicated modification process. All the 16 PAHs could be identified based on their characteristic peaks in the presence of the composited substrate, with estimated LOD as low as 0.2–2 ng·mL−1. The binary linear regression was optimized as the fitting model for all PAHs except for benzo(k)fluoranthene, with the linear correlation coefficient ranging from 0.9889 to 0.9997. Based on the developed SERS substrates and sample pretreatment, the characteristic SERS peaks of four PAHs in Chinese traditional fried food (youtiao) were identified without any background interference. The whole detection process only takes approximately 15 minutes. The results demonstrate the potential of the multicomponent on-field detection of PAHs.

Analytical chemistry, formation, mitigation, and risk assessment of polycyclic aromatic hydrocarbons: From food processing to in vivo metabolic transformation

“…However, few of them were applied in real food samples. Wang et al (2020) developed a surface-enhanced Raman scattering sensor for simultaneous detection of 16 PAHs in fried foods within 15 min, showing the potential of onsite screening of PAHs in food samples.…”

“…Supercritical fluid extraction is able to extract PAHs selectively and efficiently from complex matrices under the supercritical condition; however, the final solvent evaporation step may cause loss or degradation of the analytes (Kayali‐Sayadi, Rubio‐Barroso, García‐Iranzo, & Polo‐Díez, 2000; Ali & Cole, 2001; Amezcua‐Allieri, Ávila‐Chávez, Trejo, & Meléndez‐Estrada, 2012). Other cutting‐edge techniques that consume lower amounts of solvent and reduce experimental steps have been reported, such as matrix‐solid phase dispersion (Pensado, Casais, Mejuto, & Cela, 2005; Olson, Meyer, & Portier, 2014), membrane‐assisted solvent extraction (Rodil, Schellin, & Popp, 2007), microwave‐assisted extraction (Germán‐Hernández, Pino, Anderson, & Afonso, 2012), ultrasound‐assisted solvent extraction (Veiga et al., 2014), ultrasound‐assisted emulsification‐microextraction (USAEME) (Yebra‐Pimentel, Martínez‐Carballo, Regueiro, & Simal‐Gándara, 2013), stir‐bar sorptive extraction (SBSE) (Kolahgar, Hoffmann, & Heiden, 2002), solid‐phase micro‐extraction (SPME) (King, Readman, & Zhou, 2004; Purcaro, Moret, & Conte, 2007; Purcaro, Morrison, Moret, Conte, & Marriott, 2007; Lin, Wei, Jiang, Zhu, & Ouyang, 2016; Jalili, Barkhordari, & Ghiasvand, 2020), magnetic solid‐phase extraction (MSPE) (Zhao et al., 2011; Zhang et al., 2017), dispersive liquid–liquid micro‐extraction (DLLME) (Rezaee et al., 2006; Cai, Stevens, & Syage, 2012; Kamankesh, Mohammadi, Hosseini, & Modarres Tehrani, 2015), and the quick, easy, cheap, rugged, effective, and safe (QuEChERS) method (Ramalhosa, Paíga, Morais, Delerue‐Matos, & Oliveira, 2009; Smoker, Tran, & Smith, 2010; Gratz et al., 2011; Kao, Chen, Chen, Huang, & Chen, 2012; El Husseini, Makkouk, Rabaa, Al Omar, & Jaber, 2018; Wang, Cheng, Han, & Xie, 2020). SPME is a solvent‐free single‐step pretreatment method with low detection limits and good performance, which is a favorable pretreatment technique for PAH analysis.…”

Recent advances in the analysis of polycyclic aromatic hydrocarbons in food and water

“…In an attempt to develop a SERS method for simultaneous determination of 3 PAHs including PYR, ANT and PHE, Wang et al [ 108 ] prepared hybrid AgNPs decorated graphene as SERS substrate and reported a linear response in the concentration ranging from 0.02–2.02 × 10 4 μg/L for PYR and 0.02–1.78 × 10 4 μg/ L for both PHE and ANT, with the LOD at 0.73, 0.57 and 1.10 μg/L, respectively. In another study, a versatile SERS sensor with AuNPs decorated on doubly-oxidized graphene oxide was developed for simultaneous analysis of 16 EPA priority PAHs [ 109 ]. The typical peaks for all the 16 PAHs were identified in the SERS spectra of both standard mixture and Chinese traditional fried food (youtiao) with a LOD value ranging from 0.2 to 2.0 ng/mL, while the latter showed no significant background interference.…”

“…Taken together, compared to electrochemical sensors, a high number of SERS-based optical sensors developed recently showed a multiplexing capability to simultaneously detect 2–16 PAHs. For analysis of 16 PAHs, the SERS sensor with AuNPs deposited on GO showed a lower LOD (0.2–2 μg/ L) [ 109 ] compared to that deposited on Fe 3 O 4 nanoparticles (1.01–16.62 μg/L) [ 99 ]. Among the various SERS sensors with multiplexing capability of detecting 2–7 PAHs, the lowest LOD was shown for 7 PAHs (0.01–0.14 μg/L) with SERS-active colloidal AuNPs/NaCl [ 94 ], followed by 4 PAHs (0.04–0.15 μg/L) with porous copolymer-based colloid AuNPs [ 105 ], 3 PAHs (0.03–3.56 μg/L) with MOFs-based AgNPs [ 107 ] and 2 PAHs (0.08–0.78 μg/L) with β-cyclodextrin-based AuNPs [ 102 ].…”

Feasibility of SERS-Active Porous Ag Substrates for the Effective Detection of Pyrene in Water

“…The surfaces are generally modified by adding groups such as thiols, alkyl chains, antibodies, or -cyclodextrin ( -CD). Other strategies are based on the immobilization of PAH molecules on graphene-based supporters, to which plasmonic nanoparticles are then added [ 24 , 25 ]. As a matter of fact, PAHs do not contain any functional groups (except in the case of derivates) that could favor the metal–adsorbate bonding; hence, the chemical enhancement with SERS [ 26 ].…”