Surface　enhanced　Raman　scattering　(SERS)　is　an　ultrasensitive　analytic　technique.　However,　the　application　of　SERS　in　quantitative　analysis　usually　suffers　from　poor　reliability　due　to　the　limitations　of　currently　developed　SERS　substrates.　In　the　present　work,　aggregated　gold　nanoparticles　(a-AuNPs)　fabricated　by　Ca2+-mediated　assembly　are　dispersed　in　polyvinyl　alcohol　solution　to　prepare　a　novel　hydrogel　SERS　chip　through　a　physical　crosslinking　method.　Taking　advantage　of　the　uniform　distribution　of　SERS　active　a-AuNPs　in　the　three-dimension　hydrogel　and　the　excellent　barrier　effect　of　hydrogel　towards　oxygen　and　macromolecules,　the　obtained　hydrogel　SERS　chips　show　many　outstanding　advantages　including　high　sensitivity,　good　repeatability,　long-term　stability,　and　a　robust　anti-interference　ability.　These　advantages　enable　hydrogel　SERS　chips　to　be　used　to　quantitatively　analyse　some　complex　samples　without　complex　sample　preprocessing.　As　a　model,　the　hydrogel　SERS　chips　are　used　for　the　detection　of　triazophos　and　phosmet　in　orange　samples.　The　good　recoveries　suggest　good　applicability　of　the　hydrogel　SERS　chips　in　food　safety　detection.　This　work　provides　a　reliable　and　convenient　platform　for　the　quick　detection　and　on-site　monitoring　of　chemical　contaminants　and　would　promote　greatly　the　performance　of　SERS　techniques　in　quantitative　analysis.　©　2022　The　Royal　Society　of　Chemistry