In this research, SPSS statistical analysis program was used to analyze the data readings (output transmitted power) that appear on LCD display screen of detector. One-way ANOVA table was applied for mean transmittance value comparisons, with confidence value 95%. Indeed, it was needed to demonstrate the optical discriminatory ability (power of optical resolution) of proposed biosensor to distinguish between SCA blood samples of different blood group types and different cases of anemia.
ANOVA tables showed that the mean comparisons of data readings between groups of SCA has statistical significance, but the transmittance value of B+SC2 and B+SC3 has no significant difference (sig. =.279 0.05), that it means the proposed biosensor cannot distinguish significantly between B+SC2 and B+SC3, in figure2 the plot show clearly the result of convergence in mean value of B+SC2 and B+SC3. At the same time, the biosensor differentiates significantly between B+SC1 and B+SC2 , B+SC3. Honestly, the sample B+SC1left at room temperature for 12h and hemolysis occur, for the purpose of determination of biosensor ability to distinguish between blood groups of haemolized and intact RBC. As a results, the mean values of transmitted voltage from haemolized B+SC1 samples, that measured at power meter, was the least.
To give logical explanation of why wide reading intervals among B+SC1, B+SC2 and B+SC3 groups and between B+SC2 and B+SC3, there were several scientific interpretations that cause such fluctuations in readings of power meter, beside the blood hemolysis leads to release iron out of RBC, which increase the absorbance of B+SC1. On the other side, for comparisons between B+SC2 and B+SC3, it depends on whether B+SC heterozygotes AS hemoglobin or homozygotes SS resulting in sickle cell trait SCT (50% normal Hb and 50% Sickle Hb) and SCA phenotype respectively. The documental archive of patients did not contain such information. Generally, it was known that the absorption coefficient of blood hemoglobin is constant at certain laser wavelength and chemical structure of hemoglobin [7] ;therefore instability of sickle hemoglobin (HbS) of certain type of SCD, leads to precipitate of iron groups on membrane of erythrocyte in the form of hemichromes [8], that cause decomposition of phospholipid bilayer of red blood corpuscles of B+SC1 homozygote-as we assumed. Also there was a trail concluded that heme binding to a primary binding site of plasma membrane resulting in a noticeable large bathochromic shift, up to 38 nm[9], that quit enough to shift absorption coefficient in form of decrease transmittance power displayed by biosensor.
At that approach, we examine the ability of biosensor to distinguish between normal Hb, Hbs and iron-deficiency anemia sample, the resultant readings shows a significant deference between variables at the same blood groups (figures 3 a , b and c).
Figure3 proves that there is no fixed rule in determining the range of readings of normal blood groups compared with other pathological groups. The hypothesis is that the amount of transmitted 650nm wavelength depends on dissociated iron concentrations in membrane of erythrocyte (fig 3 a and b) [8,9].
However, fig3c represent the inverse relationship between the transmitted light and amount of dissociated hem group residues.
From the overview of fig. 3 it is found that the emitted power of the laser beam at wavelength of 650nm for iron deficiency anemia, are the less readings than normal blood samples, meaning iron deficiency anemia absorbs 650 nm more than normal blood, and this result makes sense to emphasize that there are a reciprocal relationship between absorbance and hem-group concentration of blood -regardless of blood type- according to research samples.
On the other hand, the emitted power values of sickling samples seem fluctuated compared with normal and iron deficiency anemia samples (fig. 3), where transmittance values range from the highest value for O type (fig. 3b), and the least than NO and above than ANI for A and B blood types, with exception of B+SC1 case. This finding improve that the a mount of absorbed irradiation with certain wavelength affected with presence or absence of A,B antigen -for B and A blood type ( fig. 3a and c), and O blood type (fig. 3b) respectively- as well as severity of sickling disease (heterozygote SCT or homozygote HbS) which confirmed in fig. 2.