2.2.5. Analytical Detection Capability Compared to Other Immunoanalytical Methods

The analytical performance of the above ELFIA method was compared to that of other immunoanalytical methods (immunoassays, immunosensors) reported in the scientific literature. Detection capabilities of the immunoanalytical methods are listed in Table 3. The immunoanalytical methods reported are mostly developed to be used for crop commodities (maize, wheat, barley, rice), and LODs are specified in the method descriptions as detectable ZON concentrations in the commodity (e.g., µg/kg). For this comparison, Table 3 enlists LODs in the final diluted extract according to the method specifications published. In these assays, organic solvent extracts in aqueous acetonitrile or methanol (MeOH) were used for ZON determination, but the solvent was diluted to 0.1% or below during dilution with the assay buffer to reach the detection range. LODs ranged between 10 ng/mL by an IgYbased ELISA [57] down to 0.002 pg/mL by an an optical waveguide ligthmode spectroscopy immunosensor [67]. As seen from the analytical sensitivity data, the current ELFIA method is located in the middle range of the reported procedures regarding the LOD values. Analytical detection performance can be possibly improved by using more specific antibodies, but the main advantage of the ELFIA method lies not primarily in its sensitivity, but in its utility in combined in situ application in the determination of other water quality parameters detectable by induced fluorimetry—e.g., total organic carbon content, algal density or other organic microcontaminants (herbicide glyphosate or pharmaceutical carbamazepin). In addition, the immunofluorescence module can be easily extended to other target analytes if proper antibodies are available for their detection.


**Table 3.** Analytical performance characteristics of various immunoanalytical methods for the determination of zearalenone.

<sup>1</sup> LOD: limit of detection; <sup>2</sup> IC50: half maximal inhibitory concentration; <sup>3</sup> ELISA: enzyme-linked immunosorbent assay; <sup>4</sup> AcCN: acetonitrile; <sup>5</sup> NR: not reported; <sup>6</sup> MeOH: methanol; <sup>7</sup> SPR: surface plasmon resonance; <sup>8</sup> DPV: differential pulse voltammetry; <sup>9</sup> PBS: phosphate buffer saline; <sup>10</sup> FLISA: fluorescence-linked immunosorbent assay; <sup>11</sup> ELFIA: enzyme-linked fluorescent immunoassay; <sup>12</sup> PW PI: planar waveguide operating as a polarization interferometer; <sup>13</sup> CPG: controlled pore glass; <sup>14</sup> IAC: immunoaffinity column; <sup>15</sup> OWLS: optical waveguide lightmode spectroscopy.
