Table 1 Designed linkers to add immunogenicity to chlorpyrifos based on available literature

1.

R2−NH (CH₂)_nCOOH

(Edward et al. 1993; Cho et al. 2002; Brun et al. 2005),

2.

R5−S(CH₂)_n COOH

(Goel 2013; Manclus et al. 1994; Manclus 1996; Brun et al. 2005; Alcocer et al. 2000; Sharma and Kocher 2013; Manclus et al. 1996)

3.

R5− O(CH₂)_nCONH

(Lawruk et al. 1996)

4.

R4− OCNH(CH₂)_n COOH

(Alcocer et al. 2000; Manclus et al. 1996)

5.

R1←O

(Manclus et al. 1996)

6.

R3−CH2COCOOH

(Jones et al. 2014)

7.

R3-CH3N(CH2)nCOOH

(Alcocer et al. 2000)

8.

R4−NH(CH₂)n-OH

(Brun et al. 2005)

9.

R3−NH(CH2)n COOH

(Hua et al. 2010; Kim et al. 2011; Liu et al. 2011; Qian et al. 2009; Wang et al. 2007; Liu et al. 2016; Maftouh et al. 2017)

10.

R3−CH3N(CH2)n COOH

(Kim et al. 2011)

11.

R3- NHCH2C6H6COOH

(Kim et al. 2011)