Pure lab flex3

All the experiments were carried out using analytical grade reagents used as received without any further purification. Deionized ultrapure water (18.2 MΩ·cm) was obtained with a PURE LAB flex3 (ELGA Labwater, High Wycombe, UK) and it was used throughout the present work.
For the synthesis of L-cysteine-capped Mn-ZnS QDs and citrate-capped AuNPs, zinc sulfate heptahydrate, manganese chloride tetrahydrate, L-cysteine hydrochloride monohydrate, and hydroxylamine were obtained from Merk (Darmstadt, Germany). Sodium sulfide nonahydrate, sodium hydroxide, lipoic acid, potassium tert-butoxide, bovine serum albumin (BSA), casein from bovine milk, sodium tetrachloroaurate (III) dehydrate (NaAuCl₄), sodium citrate tribasic trihydrate, N(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC), N-hydroxysuccinimide (NHS), and Tween 20 were purchased from Sigma (Schnelldorf). Finally, rabbit polyclonal anti-PSA, mouse monoclonal anti-PSA, and prostate-specific antigen standard were obtained from Abcam (Cambridge, UK).
Poly-L-lysine surface-coated microscope slides (Electron Microscopy Sciences, Hatfield, PA, USA) with an adhesive press-to-seal silicon isolator to define wells (Grace bio-labs, Bend, Oregon, USA) were used for confocal microscopy detection.

RPMI 1640 (R0833), phorbol 12-myristate 13-acetate (PMA; P1585), SIN1 hydrochloride (Calbiochem 567028), sodium chloride (NaCl, 31434M) and proteinase K (P2308) were purchased from Sigma-Aldrich. FBS (10270-106), penicillin–streptomycin (15140−122), L-glutamine (25030081), PBS (10010−015), and trypsin (15400-054) were purchased from Thermo Fisher Scientific. Stock solutions of gold ions (HAuCl₄, 1,000±6 μg Au/mL in 2% HNO₃ [v:v]), and bismuth (1,004±6 μg/mL in 5% HNO₃) were obtained from Spectrascan Teknolab. Nitric acid (67% HNO₃, Normatom for trace-metal analysis) was from VWR International and hydrochloric acid (37% HCl, ACS for analysis) from Merck. Ultrapure water used in the study was produced using PureLab Flex 3 from ELGA LabWater (18.2 MΩ/cm).

Ultrapure water (Type I, 18.2 mΩ-cm) was from an Elga Purelab Flex 3 (ELGA LabWater, High Wycombe, UK). Sodium chloride (99.9%) was supplied by VWR (VWR Inc., Darmstadt, Germany). Analytical quality grade standards of glucose (1000 mg L⁻¹), fructose, and sucrose were supplied by Sigma-Aldrich (Merck KGaA, Darmstadt, Germany). Sodium hydroxide solution (1 mol L⁻¹) and sodium acetate anhydrous (>99%) (HPLC mobile phase) were supplied by Panreac AppliChem (Panreac AppliChem, Barcelona, Spain) and Sigma-Aldrich (Merck KgaA, Darmstadt, Germany), respectively. Peptone saline solution, Man, Rogosa and Sharpe (MRS) agar and nutrient agar were from VWR (VWR Inc., Darmstadt, Germany). The alkane standard mixture for gas chromatography–mass spectrometry compound identification was purchased from Sigma-Aldrich (Merck KgaA, Darmstadt, Germany).