The Fast And Real-time Phospholipids Oxidation Determination Based On Tailoring Printable Mesoscopic Chip

Phospholipid is an important component of cell membrane.Phospholipids are amphiphilic molecules with hydrophobic fatty acid chains and hydrophilic moieties.And they are easily oxidized due to their unsaturated fatty acids in the presence of oxygen and other oxidants.Intramuscular phospholipid is the main substrate of lipid hydrolysis and oxidation in the process of meat processing.Under the action of lipoxygenase,free radicals and metal ions,intramuscular phospholipids are oxidized.Some of oxidation products are the main source of precursors for dry-cured meat flavors,but some oxidation products are harmful to human body.Many kinds of diseases are closely related to phospholipids oxidation such as ovarian cancer,atherosis,diabetes,and cardiovascular diseases,and so forth.Therefore,it's an active area of research for the analysis and identification of phosphatide oxidationRecently,photoelectrochemical sensor has become the focus because of its low background signal,high sensitivity,low-cost equipment and easy miniaturization.Inspired by the solar sensitized dye cells(SCs),a printable mesoscopic chip(PMC)for detection of phospholipids oxidation was designed and fabricated.The content and results were given below.1.The preparation and the feasibility analysis of the fabricated PMCIn this chapter,the PMC was designed to detect phospholipid oxidation.In this contribution,TiO2,ZrO2 and carbon films were screen-printed on the FTO glass substrates layer by layer according to design diagrams and experimental conditions.The feasibility of PMC for determination of phospholipids oxidation were investigated by scanning electron microscope(SEM),UV-vis spectroscopy,cyclic voltammograms(CVs)and electrochemical impedance spectroscopy(EIS),etc.The results showed that phospholipids(soybean lecithin was used in this paper)can meet the good infiltration.Analyze the temporal evolution of J-V curves of the soy lecithin no-dipped/dipped PMC.For the pristine PMC,the Jsc is nearly 0 due to the barrier insulating mesoporous ZrO2 between TiO2 and carbon.After dip-coating soy lecithin,it could work as sensitizer for PMC and then generate photo-induced carrier.Meanwhile,it acted as a bridge between TiO2 and carbon films,therefore an enhanced Jsc was observed.2.The determination of phospholipids oxidation probing via PMCIn this chapter,C/ZrO2/TiO2 mesoporous chip was used to detect phospholipids with different oxidation degrees,and light and temperature varying methods were used to treat phospholipids,simulating the phospholipid oxidation system.Under light conditions,the Jsc decreased from 0.043 mA·cm-2 to 0.011 mA·cm-2.And the soy lecithin dipped PMC stored in dark,and the Jsc was relatively stable.Then the result showed the temporal evolution of J-V curves of the soy lecithin dipped PMC at 40?.The Jsc of the PMC had an obviously continuous decreased from 0.048 to 0.018 mA·cm-2.This is corresponding to the stable Jsc when stored at 0? for different time.In order to demonstrate the relationship between Jsc and oxidation level.Moreover,the Jsc of PMC has a good coincidence with POV of the soy lecithin,fitting the linear regression equation for phospholipids oxidation degree.The fitting expression was POV=-1580.4×Current+87.196.The Jsc of the PMC increased with the increment of the soy lecithin content and exhibited a good linear relationship with the soy lecithin concentration ranging from 1 to 5 mg.The linear regression equation was Jsc(mA·cm-2)=0.02165×mass(mg)-0.02478,with a correlation coefficient(R)of 0.9948 and a low detection limit of 0.367 mg,which was calculated from the ratio of signal to noise ratio(S/N)of3.In order to verify the usefulness of the PMC,other samples were determinated.As indicated by the results,the PMC could be applied in practical samples satisfactorily and efficiently.In addition,the mesoporous chip has good anti-interference ability to common substances in meat,including linoleic acid,myristic acid,arachidonic acid,palmitic acid,cholesterol and hydrophilic glucose.Moreover,an analytical performance comparison of some determination methods reported by previous papers and the PMC we prepared was performed.From the result,we can conclude that the proposed PMC has a higher sensitivity and a lower detection limit than those previous reported models.The stability of the PMC was investigated by a series of consecutive measurements at low temperature(0?).The results showed that the stability and reproducibility of the PMC were satisfactory.