Hi itsbaala,

Refer below code.

HTML

<asp:GridView runat="server" ID="gvDetails"></asp:GridView>

Namespaces

C#

using System.Data;
using System.Net;
using Newtonsoft.Json;

VB.Net

Imports System.Data
Imports System.Net
Imports Newtonsoft.Json

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    string url = "https://api.elsevier.com/content/search/sciencedirect?query=gene&apiKey=API_Key";
    WebClient client = new WebClient();
    string reply = client.DownloadString(url);
    Root root = JsonConvert.DeserializeObject<Root>(reply);
    DataTable dt = new DataTable();
    dt.Columns.Add("LoadDate");
    dt.Columns.Add("DcIdentifier");
    dt.Columns.Add("Link");
    foreach (Entry entry in root.SearchResults.entry)
    {
        DataRow dr = dt.NewRow();
        foreach (Link link in entry.link)
        {
            dr["LoadDate"] = entry.LoadDate;
            dr["DcIdentifier"] = entry.DcIdentifier;
            dr["Link"] = link.Href;
            dt.Rows.Add(dr.ItemArray);
        }
    }
    gvDetails.DataSource = dt;
    gvDetails.DataBind();
}

public class Root
{
    [JsonProperty("search-results")]
    public SearchResults SearchResults { get; set; }
}

public class SearchResults
{
    [JsonProperty("opensearch:totalResults")]
    public string OpensearchTotalResults { get; set; }
    [JsonProperty("opensearch:startIndex")]
    public string OpensearchStartIndex { get; set; }
    [JsonProperty("opensearch:itemsPerPage")]
    public string OpensearchItemsPerPage { get; set; }
    [JsonProperty("opensearch:Query")]
    public OpensearchQuery OpensearchQuery { get; set; }
    public List<Link> link { get; set; }
    public List<Entry> entry { get; set; }
}

public class OpensearchQuery
{
    [JsonProperty("@role")]
    public string Role { get; set; }
    [JsonProperty("@searchTerms")]
    public string SearchTerms { get; set; }
    [JsonProperty("@startPage")]
    public string StartPage { get; set; }
}

public class Link
{
    [JsonProperty("@ref")]
    public string Ref { get; set; }
    [JsonProperty("@href")]
    public string Href { get; set; }
    [JsonProperty("@type")]
    public string Type { get; set; }
}

public class Entry
{
    [JsonProperty("load-date")]
    public DateTime LoadDate { get; set; }
    public List<Link> link { get; set; }
    [JsonProperty("dc:identifier")]
    public string DcIdentifier { get; set; }
}

public class Authors
{
    public object author { get; set; }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    Dim url As String = "https://api.elsevier.com/content/search/sciencedirect?query=gene&apiKey=API_Key"
    Dim client As WebClient = New WebClient()
    Dim reply As String = client.DownloadString(url)
    Dim root As Root = JsonConvert.DeserializeObject(Of Root)(reply)
    Dim dt As DataTable = New DataTable()
    dt.Columns.Add("LoadDate")
    dt.Columns.Add("DcIdentifier")
    dt.Columns.Add("Link")
    For Each entry As Entry In root.SearchResults.entry
        Dim dr As DataRow = dt.NewRow()
        For Each link As Link In entry.link
            dr("LoadDate") = entry.LoadDate
            dr("DcIdentifier") = entry.DcIdentifier
            dr("Link") = link.Href
            dt.Rows.Add(dr.ItemArray)
        Next
    Next

    gvDetails.DataSource = dt
    gvDetails.DataBind()
End Sub

Public Class Root
    <JsonProperty("search-results")>
    Public Property SearchResults As SearchResults
End Class

Public Class SearchResults
    <JsonProperty("opensearch:totalResults")>
    Public Property OpensearchTotalResults As String
    <JsonProperty("opensearch:startIndex")>
    Public Property OpensearchStartIndex As String
    <JsonProperty("opensearch:itemsPerPage")>
    Public Property OpensearchItemsPerPage As String
    <JsonProperty("opensearch:Query")>
    Public Property OpensearchQuery As OpensearchQuery
    Public Property link As List(Of Link)
    Public Property entry As List(Of Entry)
End Class

Public Class OpensearchQuery
    <JsonProperty("@role")>
    Public Property Role As String
    <JsonProperty("@searchTerms")>
    Public Property SearchTerms As String
    <JsonProperty("@startPage")>
    Public Property StartPage As String
End Class

Public Class Link
    <JsonProperty("@ref")>
    Public Property Ref As String
    <JsonProperty("@href")>
    Public Property Href As String
    <JsonProperty("@type")>
    Public Property Type As String
End Class

Public Class Entry
    <JsonProperty("load-date")>
    Public Property LoadDate As DateTime
    Public Property link As List(Of Link)
    <JsonProperty("dc:identifier")>
    Public Property DcIdentifier As String
End Class

Public Class Authors
    Public Property author As Object
End Class

Screenshot

Using your code result got success thank you.

protected void Button1_Click(object sender, EventArgs e)
{
    string url = "https://api.elsevier.com/content/search/sciencedirect?query=gene&apiKey=APIKEY";
    WebClient client = new WebClient();
    string reply = client.DownloadString(url);
    Root root = JsonConvert.DeserializeObject<Root>(reply);
    DataTable dt = new DataTable();
    dt.Columns.Add("LoadDate");
    dt.Columns.Add("DcIdentifier");
    dt.Columns.Add("Link");
    dt.Columns.Add("Link_ref");
    dt.Columns.Add("dctitle");
    foreach (Entry entry in root.SearchResults.entry)
    {
        DataRow dr = dt.NewRow();
        foreach (Link link in entry.link)
        {
            dr["LoadDate"] = entry.LoadDate;
            dr["DcIdentifier"] = entry.DcIdentifier;
            dr["Link_ref"] = link.Ref;
            dr["Link"] = link.Href;
            dr["dctitle"] = entry.dctitle;
            dt.Rows.Add(dr.ItemArray);
        }
    }

    string sci = "scidir";
    DataView dataView = dt.DefaultView;
    if (!string.IsNullOrEmpty(sci))
    {
        dataView.RowFilter = "link_ref = '" + sci + "'";
    }
    gvDetails.DataSource = dt;
    gvDetails.DataBind();
}